Buy any of the 6800's you find or any of the 6600 GT's you find. Both are very nice cards. You won't get a MASSIVE upgrade from the monster 9500 Pro (DAMN good card) unless you go for the 6800 though...the 6600 GT would be an upgrade, but not that much of an upgrade. I'd just go with one of the GeForce 6800's. Mine is an eVGA and serves me really nicely (6800 GT). Yes, LE does mean "Le sucks." I think I'll start using that from now on, it's a good one.
*EDIT* I'd get <A HREF=http://www.newegg.com/app/ViewProductDesc.asp?description=14-130-202&depa=1>this</A> one.
As for your RAM, just get cheap Crucial or Corsair or Kingston or Mushkin. 1 GB sounds very nice.
-Lasereth