Opteron's have made their way into desktops due to their overclockability. You don't seem to be doing any overclocking. Which is fine and that CPU will serve you very well. Yet, if you are planning on overclocking, that RAM isn't the best choice, nor is that motherboard.
I've built with that MOBO many times and although it's a fantastic, solid, reliable MOBO... It's just not Overclocking quality. Sure it has some OCin' features, but it's not built like a DFI or a Newer ASUS.
May I recommend another thing, go with a SATA HDD, instead of a IDE HDD. There are too many reasons to explain.
These are just my opinions.