Only problem I see with that build is that you bought value RAM. You bought an Opteron, so I'm guessing that your going to be doing a fair amount of overclocking. The value RAM is going to really limit your overclock because you have a good overclocking CPU and bad overclocking RAM.
If it's money you are concerned about, you should have bought this RAM.
We just used it on a recent computer build for one of our teachers and it's already running at 460 MHz. I'm positive that it can still go higher, just gotta stop with the CPU because it's using OEM heatsink & fan.
If money isn't a problem, go with something better than I showed in the link.