If you can afford the 8800GT then definitely go for it. It's a better card in pretty much every respect. If the cooler is too loud there are quite a lot of aftermarket coolers that you could slap on there.
Isn't the 8800gts 512mb not much more money than a gt because of the mark up? And isn't a gts quiter? If so I would just get that since a good aftermarket cooler is a bit of cash.
However my guess is the OP's budget is lower than that so if he cares about noise then its a toss up for which one to go with...