AMD used to be amazing - far, far superior to Intel. Sadly they've fallen behind quite a bit in the last 3-5 years, so nowadays I'd recommend going with an Intel chip as well. Not because Intel are inherently better than AMD, but because these days their chips tend to be faster and more reliable, at similar costs. Even when clock speeds are the same, I'd say current-gen Intel CPUs have an edge over current-gen AMD CPUs. Hopefully AMD will be able to catch back up and reclaim their position of dominance, but I don't see that happening any time soon.
Graphics cards are a slightly different matter. In general, I'd say if you can afford an Nvidia GPU, and it's not too ridiculously huge and over the top, then it's probably worth going for it over an AMD card. AMD cards usually offer similar (or sometimes superior) performance hardware-wise, and are significantly better value for money, but in terms of driver and software support, and features other than pure graphics power, they are significantly inferior to Nvidia. The most recent ones do also have an unfortunate tendency to run pretty hot, which can be an issue - but I don't know if Nvidia cards currently have the same problem or not.
But yeah, your current build seems fine. I'd second the suggestion of waiting a week or two, since the prices of your components will drop quite a bit as soon as Ivy Bridge is out, but other than that, no real comment.
