I intend to build my own, something like that. Except with the Nvidia graphics card, latest, and possibly liquid cooling. Including a motherboard capable of overclocking. I have most of my list finished for it, just need to get the funds then.
Thing about the Intel 7I CPU is that you really don't need it for gaming. Games are not programmed to take advantage of it properly. You're only going to be getting a bare few extra frames from it when running Crysis (I blame Crysis for this though, it had shoddy coding), but excellent for multi-media editing purposes. It's like buying a really fast car that would require you to break the law and being insane to actually use it properly. Although it's something to last you for a long time, no doubt.
The AMD cards is a good idea, getting the most out of your PC at a fairly cheap price. Again, Nvidia is better, but your not going to be using it fully at any time for any game out there. I refer again to the fast-car example.
If you want a powerful gaming rig, without the flash of a fast car, an AMD high end CPU and AMD Radeon graphics is what you'll want. Also, spend the extra for a 2 ms refresh rate on a wide-screen. You may be sacrificing an enormous scree, but nowadays you can get a fairly big screen with a 2 ms refresh rate, which prevents ghosting and allows you to wear 3-D glasses. I'd say the nerdgasmic experience is worth it.