My advice is to buy a higher wattage PSU when you buy that rig. Something along the 700+watts. It comes witha 350watt PSU, but I don't feel safe with that specially if you're running 8 cores. Also, the you'll need a stronger PSU when you start upgrading your GPU, might as well get a jump start on it now.
edit..
http://www.microcenter.com/product/4...sktop_Computer
A little out of your price range, but it's using Intel I5 new gen, and NVidia GTX 650, also 8g 1600 DDR3. It doesn't say what the PSU wattage is, but I don't imagine it to be less than 500. Better ask first tho, coz you might need to swap out the PSU again.