Tutu basically takes the entire engine of the 2nd game and puts it into the first. So you can do things like modify the NPC's to use the second game's character sub classes (making Kivan an Archer rather than a generic ranger for example, since nobody really uses Kivan for anything other than archery).

Also means you can yourself use the BG 2 character classes, and you get to pick and choose from the game rules. So for example I always keep the BG 1 summoning spells (which were nerfed in the sequel) but kept other things which were buffed.

If you want a challenge, go for Ascension - it doesn't suit first time players as much. You'll get the most out of Tutu if you've already got some understanding of how the game works and what's different between the two games, but I'll never play the original without Tutu again.

Really, you should get Ascension as well in my opinion. You get the option to pick and choose exactly which components you want to install, so even if you want to skip the more challenging content (and hoo boy, is it ever), you should definitely get it just for the tweaks to To B's pacing and plot.

And I'm adding my voice of support for Tutu as well. I will never play BG 1 without it again. And there's all sorts of fun mods written for a Tutu-ified BG 1. The NPC project stands out.

Really, there's excellent stuff for both games out there on the modding sites, chief among them some bugfix and balance packs.

So...if I get Ascension, I have the option of not being forced to fight a Brainwashed And Crazy Imoen? Because that's the main thing that's deterring me from wanting to get it.

Look up the Gibberlings Three, which is the home page of the Tutu project - it has extensive FA Qs and the forums there have even more, so you'll be able to get all the help you need there!

Agreed with the above. REALLY pay attention to the readme as well. Tutu can be a bit of a bear to install if you don't RTFM. And as for the Ascension question: Not precisely. You can't avoid it. But you don't have to kill her either if you don't want to. The solution becomes obvious when the situation arises.

And for mods:

The Gibberlings Three The Pocket Plane Group - since overtaken by G3 above, but there's some quality stuff there, including banter packs and whatnot.

Easy Tutu makes it very easy to install though, since you just go through the options in sequence. You still have to pay attention to the instructions though to make sure you get things like the mods, patches etc in the right order. Especially since not all mods work with each other, and some combinations will flat out require you to uninstall everything and start over if they end up overwriting key files in each other.

Research well the mods you want and make sure you check out their mutual compatability. Don't worry though - whatever questions you might have about that have already been asked a thousand times, for any given combination.

Ok, I have everything plus the mods I want installed, and since the Bioware forum proved so helpful on this matter, I might as well ask here too: Which weapons/armor/etc are good for each member of the canon party? (Imoen, Jahiera, Khalid, Minsc, and Dynahier).

Oh, and just for reference, my CHARNAME is a Cleric with proficiency in Mace and sword/shield style.

Depends on the resolution you use I believe how much space there is there. Could always ask around the modding community and find out if such a thing exists or could be made! I would be surprised if nobody has tried anything of that nature to be honest.

Where do you live? The UK sells all four together.

In the U.S., darn it. Well, hopefully I'll eventually find it here.