Why not buy a Dell inspiron 580 desktop all that you might still need is the video card but I doubt it from what you are talking about doing with it. it does have a pci-express x16 slot
He's not gonna be doing much in the way of gaming on Lynnfield integrated graphics; and I wouldn't bet that the Dell PSU can push a GTX 460.
So you're looking at $500 (plus tax!) for a dual-core i3 550 Inspiron 580 that still needs a video card ($100) and probably PSU ($35). It does come with Windows 7. But it also comes with all 4 DIMMS already filled.
Oh, and the Inspiron 580 doesn't even qualify for free shipping at $500. I just put one in my cart and am looking at $49 in shipping and $33 in tax on a $499 system. So that would be $717 total for just a dual-core i3 550/GTX 460.
As David said... $605 i5 2500k build. It has the God-tier processor, the fastest 7200RPM hard drive on the market (no telling what the Inspiron 580 has), SATA 6Gb/s and USB 3.0, 2 DIMMS open, a case that looks to have much better cooling, and he doesn't pay tax unless he lives in California.
I honestly would find it VERY hard to recommend anything between this and the $370 AMD build. Upping video card doesn't make much sense since it's such a deal at $99 and the AMD isn't going to really take advantage of a $170+ video card (and the Sandy Bridge doesn't have the budget.) And upping the CPU to anything significantly better puts you so close to the i5 2500k
This isn't bad:
http://www.newegg.com/Product/ComboD...t=Combo.581470
Phenom II X4 955 with Gigabyte GA-800GMA-UD2H
But we're within $90 of Sandy Bridge.