Why not a Lenovo X61? I configured an X61 on their site with 2gb RAM, a 120GB HD, and the high-end display for $1750.
Double-seconded. :-) I TA'ed for our Intro to Engineering course and this is the first year we required freshmen to get tablets. There were various HPs, Compaqs, and others, but I really liked the X61's. I confess I'm a Thinkpad owner and have really come to like it a lot, so I might be biased. None the less, I think the X61 was the most professional looking and least bulky. Whatever you decide, make sure the stylus is magnetic and not pressure based.
PS I recommend Windows XP and not overdoing it on the ram. 32-bit OS's can only address 4gbs anyway and if you get XP you'll be set with 2gb. If you get more ram, that's a shorter battery life!