First run the PSU calculator to verify your load. Run it as is, and with the additional components that you might be adding i.e., additional graphics card etc.
Edit: Be careful to only set single processor even thought it is a dual core because it is only one socket.
http://www.extreme.outervision.com/psucalculator.jsp
I just ordered this PS it is as solid as a rock and on sale 25% off. It is a little longer, so be sure it will fit your case.
Newegg.com - PC Power & Cooling Silencer 610 EPS12V EPS12V 610W Continuous @ 40°C Power Supply 100 - 240 V UL, cUL, CE, CB, TUV - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16817703005