Deadguy is right, in that the 10000rpm isn't going to do you much good compared to the 7200, 10000 are more benificial in servers as he said.
I hace a 40GB Wesern Digital 7200 and it is plenty fast for anything I am doing, games and downloads mostly, and transferring to my other HD and or cd-r's, it is real fast, and quiet.
Go with the 7200 bigger drive, you will be glad you have the space, and not the speed, that again, won't be that much different.
Blake