I have been thinking about getting X-Com UFO Defense and X-Com Terror from the Deep from GG.
However, I would much rather get them through GOG if I could. I am wondering how long before we will see these games here as I would rather only buy them one time (from GOG preferably).
What do you all think the Real possibility is of getting these in a reasonable time frame? Makes me wonder about just buying them.
I bought them once already through Steam, but I no longer use Steam so they are gone.

You no longer use steam or you did something to get your steam account banned? If your steam account is still in good standing just load it up and play them there, as you already purchased them previously. That way you can play them and wait until such a time as GOG gets them.

Tell steam not to start up when the computer starts.
If you buy it from GG which you seem to not really want to do (or why would you be asking for it here) you're just continuing to throw money away. I'm not saying spend any more money with Steam but if you've already purchased the games why just throw them out?

I'm similar, I abandoned my old account that I had bought a few games on because I saw it for what it was. I managed to finally get Steam to transfer just Valve games (was like getting blood out of a stone though), so although I do use Steam now just for them, I will never ever buy a non-Valve game from Steam again. Too many uncertainties and dissatisfactions about the software and service as a whole. GOG and those like it ftw.
To the issue at hand - I'd buy from either GG or [url=http://www.direct2drive.com/7575/product/Buy-X-Com:-UFO-Defense-Download]D2D[/url], whichever is cheaper for the time being. It's not much moneh, and while they don't have bonuses your purchase will at least send signals of support to the publisher for DRM free games.

Heh, you should check the folder in Steam for those games. The only thing Steam does when you start those two game, is run a batch file to start DOSBox. The actual games are actually not implemented in Steam at all, so you can move them out of the folder, and use a regular install of Dosbox instead.
EDIT:
This actually goes for all Dos games that use Dosbox in Steam.

I am not that savvy, could you give a step by step on what to do and how to do it? I mean the DOSBox part of the equation.

Just wait it out a while more Faithful. It'll be out on GOG, as soon as idiot publishers start to realize that GOG is in no way more inferior to Steam.

Upon further inspection, I noticed that not even the Dosbox is integrated. You can actually just copy the folder from Steam, place it where ever you'd like, and use Dosbox.exe to run it, without modifying anything.

Will this cause a problem with Steam? I mean void my usage? I do not use it but do not want to have any issues with Steam either. I should wait for GOG to get it and buy it again.

The games are DRM free. Meaning no ties to Steam and no means of Steam knowing that you're playing the games without the Steam client. Some games don't use the client for DRM. It's not a requirement that they do, but many publishers see it as advantageous.
Ultimately it would only be for a financial matter (suspected fraud) that they'd ban your account.

Really, it seems like you had already made up your mind before you started wondering...

brandy and mister whiskers..