350w is actually more than enough.
40w Max for the 8500GT
15w Max for HDD
15w Max for CDROM
30w for Mobo
50w for Case Fans
Total 245w - And that is with everything maxed.
Normal load will be much lower.
So, you are really not concerned about total wattage.
Just look for a good quality PSU.
Here are two good examples.
The first one is just fine for your setup.
The second one would be better if you ever wanted a top of the line video card.http://www.newegg.com/Product/Product.aspx?Item=N82E16817703010