I almost never pick energy weapons for my combat skill, so I need a little help here.
Without counting Solar Scorcher, what is the most dangerous energy weapon in the game?
Where you guys get more ammo for energy weapons? They cannot be found in plenty amounts like JHP, unfortunately.
And if you can recommend a build to me, I would be grateful.

Which game, Fallout 1 or 2? In Fallout 1 I think the best energy weapon is an enhanced Plasma Rifle. But you won't find ANY energy weapons until later in the game, so an energy weapons focused build might be tricky. One thing you can do is have a different combat skill (like small guns) for use earlier on and then switch to energy weapons at the end, possibly by using the "Tag!" perk to tag the energy weapons skill late in the game. I did this with my first character... used small guns for most of the game but then also got good at energy weapons at the end for the tougher enemies.

Fallout 2 might have more useful weapons... I know you can get laser pistols in New Reno from one of the mafia families, for example. I'm not sure what the best energy weapon in Fallout 2 is.

Sorry, forgot to say! Fallout 2.

Don't forget the plasma pistol you can find in the sewers under Necropolis in Fallout 1. It's not a bad little thing, just a little underwhelming compared with the Enhanced Plasma Rifle or the Laser Gatling. And at least it doesn't use the fusion packs, which means you're not eating ammo you'll be using later for other, larger guns.

Personally, I'd recommend a character with excellent stealth, or excellent bargaining skills, in Fallout 1 if you go for energy weapons. It's more useful than another combat skill you won't use later.
Ah. Well, for Fallout 2, if you do want a secondary combat skill, Unarmed is fun. Incredibly fun. So there's always that.

In FO2, Pulse rifle and pistol from Brotherhood in San Fran. But you're probably 3/4 through the game by that time.

Generally, plasma is good - laser is bad.

In FO1 you can get by until getting to the plasma pistol under necropolis, in FO2 a secondary combat skill is almost certainly necessary (and unarmed does come handy, but anything works really).

I recommend the following build:

S:6 (laser, plasma and pulse rifle need 6 str)
P:7-8
E:4 or 6
C:2 or 4 or 6 depending on the number of party members you want (taking magnetic personality at level 3 is better than raising cha by 2)
I:8-9
A:10
L:6-8

Traits: gifted and maybe another one
Skills: energy weapons, speech and maybe lockpick or doctor or unarmed

Perks:
3: magnetic personality (if you want more than 1 NPC)
6: Awareness
9: better criticals
12: lifegiver
15: bonus rate of fire
18: action boy or living anatomy

In the beginning you can fight unarmed or use small guns even with low skill. You'll find guns and bullets magazines to raise it for free.
The first energy weapon you might find is the solar scorcher. It's a great weapon and powerful enough until the endgame.
In New Reno you can get a laser pistol (Mason will also raise your skill by 5 if you ask him) if you work for the Salvatores. Kill and loot them after doing their quests. Afterwards you can work for the Wrights to get access to the Sierra Army depot where you can find a plasma rifle.
The guy below the New Reno Arms shop will upgrade those energy weapons for free, don't forget to take the ammo out first for free new ammo.

At level 13+ there's a chance to meet a trader who sells an alien blaster in a random encounter in the north. If you have random encounters in areas with mountain caves it's worth entering them. There's a chance to find humans with energy weapons there.

The first option (weak character that later becomes very powerful).
Since I want Cassidy in my team, I'll be a good samaritan. :P

If you intend to talk your way out of most situations and will simply throw a lot of points into Energy Weapons later, you could always try out Good-Natured. It can give you that edge you need on diplomacy in the early game.

For my part, I'd recommend against Gifted. A character who is avoiding combat in early levels probably can't much afford to lose several major skills for the sake of a few stat points. However, Gifted can be the only way some builds ever obtain Sniper, so your mileage may vary.

Ok then, here's the basics:

ST: 5
PE: 7+ (need 8 for sniper at 24, you get +1 from a memory module)
EN: 4+ (wouldn't recommend more than 4)
CH: 2+ (depending on how many NPCs you want)
IN: 5+ (need 6 for bonus rate of fire at 15, you get +1 from a memory module*)
AG: 10 (ideally, you could go with 9 if you want to substitute a perk for Gain AG)
LK: 8 (you get +2 from the correct zeta scan from NCR or SF, 10 LK = 100% crits once you get sniper at 24)

How you distribute the leftover points comes down to personal preference. Personally I prefer higher IN for more skill points.

*Note: you have to not be evil to be able to get the IN memory module, since you can only get the quest to enter SAD from Orville Wright if you're not evil.

Traits: this also comes down to personal preference. If you prefer aiming, then I'd recommend Gifted and Small Frame (or One Hander IF you only plan on using one handed energy weapons, such as laser pistols or the alien blaster). If you don't care for aiming, then I'd recommend Gifted and Fast Shot. Once you get Sniper at 24 you'll be getting 100% crits with your 10 luck anyway, and Fast shot typically lets you get off one or two more shots per turn than if you were only making aimed shots.

Skills to tag:
Energy Weapons (going to be taking this to about 150 eventually, should be good enough for shooting at long range as well as in the dark)
Speech (always useful, raise this early on, no more than 100)
Lockpick (same as speech)

Perks by level:
3: Awareness (lets you see health, weapon and ammo of targets, useful for prioritizing your kill order)
6: Quick Pockets (filler, not mandatory, but useful because you can go into your inventory and reload as many weapons and use as many stims as you want for only 2AP)
9: Better Criticals (chance for instant death crits, nice)
12: Living Anatomy (straight up +5 damage per shot, need Doctor at 60 though so plan for this)
15: Bonus Rate of Fire (1 less AP per shot, if you have Fast Shot you have 2 less AP per shot)
18: Action Boy 1/2 (not too useful until you get the second)
21: Action Boy 2/2 (12 AP lets you squeeze off a lot of shots per turn with Bonus RoF and Fast Shot combined)
24: Sniper (100% crit with 10 LK)

And that's it. For this build, I'd recommend skipping as much as the temple of trials as you possibly can. Early on, just stick with Unarmed or a Melee weapon. Be sure to get training from Lucas and Jordan in Arroyo. Also be sure to get the Sharpened Spear from Mynoc so that you can later give it to Sulik. You need 50 Speech to convince your aunt to give you the flint (or just steal it from her). Once you get to Klamath, you can get some more Unarmed and Melee training and get Sulik as well. He'll come in handy until you can later swap him out for Vic and then Cassidy. I'd recommend getting the car as quickly as possible including the fuel cell regulator upgrade. I'd also recommend heading straight to New Reno, getting it stolen and then getting your free battery source going from fooling T-Ray (80 Speech should be plenty, reload if it doesn't work). After that I'd recommend buying the upgrades from T-Ray for trunk space. This will come in handy since next I recommend heading straight to SF and getting the Vertibird quest, then heading to Navarro and hoping that you don't encounter any Enclave patrols. Good luck.

Thanks for the help guys!

Someone knows where to find the Solar Scorcher in killap's Restoration Project (v.2.1.2b) ?

Not sure, but it used to be in a special encounter you either run into or don't (portal to a vault). Wouldn't expect killap to change stuff like that.

I have a monstrous bad question.
What's the EPA?