Any ATX will
I suggest you contact the PSU Tier list and pick a tier1/2 PSU
I prefer XFX if budget matters, Seasonic overall or bequiet dark power if money is no concern but you wanna go virtually silent
As for the Watts, depending on your system you'll need 400-750W.
Best you post the entire system so we can take a look at it and determine how much power you'll need