Upgrade to the 4400+ Toledo...there isn't THAT big of a difference betwenn 7800GT and 7800GTX, and if it were me, I would just buy a 6800 GT then buy a bad arse video card next year when the DX10 cards hit.
Hmm...what graphics card will you get if you don't get the 6800GT and get the 4400 Toledo? You could always do that and pick up a 6800NU which is still a very capable card.
it depends with you. i think 17" is fine with me. i mean my 17" CRT 16" viewable is fine with me. getting a 17" LCD moniotor sometime in OCt. i want to see what the difference is. 4400+ >19" LCD