Won't really help with performance but I much prefer modular PSUs. If you can afford it, consider using a corsair HX model instead.
I'm sure you are aware but remember that you'll need a 64bit OS to access all of the 8GB of RAM.
Again it's an additional cost, but 2TB drives have a better price / TB ratio.
I think you'd do well to not buy a B3 version of the motherboard now, but make sure you get this version as it resolves the Sandybridge SATA2 connector issue.