It seems odd there's no thread on which version to use or mods to add for the first game. PC gaming wiki doesn't really mention anything either. So this thread is both what I'm doing for my install while asking if anyone knows better.

VERSION
Gog used to offer a 35396 version which had problems talking to NPCs in upper hadar. As of this writing, gog offers a 35398 version. I guess I'll see if there are any bugs with this.

MODS
I keep a separate folder for mods I add to games so if I ever uninstall a game, I'll still have the mods I used, and can also get an idea of what I've already installed. From my very old install I have:

Interface 1.7
http://forum.fulqrumpublishing.com/showthread.php?t=4033
This offers a few changes to the game, but since it's from 2008 I'm going to skip it in favor of the gui mod.

KBTLEnglishGrammarSpellingPatchV1.3
http://forum.fulqrumpublishing.com/showthread.php?t=27813
This offers to fix spelling errors in the english version. Don't know if it's needed in gog's version, but I don't think it can hurt, so I'm adding it.

GUI mod
https://www.moddb.com/mods/kbgui
In addition to bigger fonts it also shows creature resistances, which is very nice. Adding this one.

Moddb also offers a camera mod which lets you pull far away but also kind of ruins immersion. I'm skipping this, though it's personal taste.