PSU anybody?

[Jascomputerguy]

Hi Everybody,
I am going to be building my first computer within a month or so and I am having trouble with a couple different aspects of it but my main concern is my power supply. I am going to be running an amd phenom II 955 BE, foxconn A7DA-S 790gx mb, 4 gig ddr3 mem,and an xfx 4870 gpu, and at one point I plan to install another 4870 for crossfire. So what I am having trouble with is how many watts I need to go with, I know I don't need any 1000 watt monster and I know 350 watts wouldn't give it enough power so I need your help to find a happy median. The links to all of the parts are below.

Motherboard- http://www.newegg.com/Product/Product.aspx?Item=N82E16813186168

GPU- http://www.newegg.com/Product/Product.aspx?Item=N82E16814150394

CPU- http://www.newegg.com/Product/Product.aspx?Item=N82E16819103674

RAM- http://www.newegg.com/Product/Product.aspx?Item=N82E16820231180

 

[Niklas_13]

Antec TP 750 http://www.newegg.com/Product/Product.aspx?Item=N82E16817371025 99.99