So, I just installed BGT, and applied the fix pack, tweak pack, the two Unfinished Business mods, and the widescreen mod. Besides those, are there any other mods (banter packs etc) that would make for the best overall BGT experience?

The main one you still need for an ideal experience is the BG1 NPC Project, that adds so much more life and personality to each character BG1. It's really difficult to go back to a vanilla BG1 experience once you've played with the NPC Project installed, as it makes the game feel much more consistent with the tone and interactivity levels of BG2.

great game man

I wrote this message with my bepo keyboard

I would take the widescreen mod off. It will make your saves incompatible if you need to change resolution, and it looks terrible. I played with it for a few hours before I was sick of it and started over. To each their own, of course, but I hear more bad than good from most folks, and I'd agree with the bad.

Get "The Vault" mod. Its one of the best ever made.