I was talking it over with a friend who knows more about hardware than I do, and he assures me that I made the right choice by going for an Opteron. Plus, I will definately be overclocking to at least 2.2 GHz on each core.
I never really liked my NV8 motherboard anyways. I only bought it so I could use a PCI-E graphics card, but it is definately a low-quality motherboard, basically the kind you find in retail PCs.