Essentially Ultra ATA is the same thing as Parallel ATA aka IDE aka UATA aka PATA blah blah. A older standard.
Your mobo supports 2x SATA connections, and SATA is the newest.
Now I dont know if your current drive is SATA or PATA, I'll assume PATA being 3~ years old.
Speed/quality wise go with SATA. (The sata drive really should be your OS drive though, a sata for storage and PATA for OS is a bit of a backwards thing.)
SATA is the new standard pretty much, and they are fairly cheap.
400+ gig for $120~
New Egg SATA Drive Listing
---- Edit ----
Come to think about it, the best thing for you if you can take the hit.
Buy a SATA drive of say... 350/500 gb. Partition it so its like 80gb / 200 / 200 (at least this is what I do so Defragmenting goes a bit smoother and quicker on the drives i need them to be.)
Reinstall Windows on the 80gb, and keep you older drive (still has all the data on it) and copy stuff over.
It makes for a easier fresh start, and you'll have a MUCH faster drive. (Assuming your old drive is not SATA!)