see no benefit in paying such a large premium for a processor that will only be "the best" for a few months, but it's your money and you will decide on how to spend it.
I would at least consider taking a small step back for almost half the price by getting the i7 970 which is still a six-core Gulftown processor:
Newegg.com - Intel Core i7-970 Gulftown 3.2GHz 6 x 256KB L2 Cache 12MB L3 Cache LGA 1366 130W Six-Core Desktop Processor BX80613I7970
You can spend more on a GTX 570 or 580 then (if your intention is to max out your budget), since this PC, I assume, is for gaming and not for CAD or video editing. Two GPUs is almost never better than a single better GPU.
Why do you want to open up an external hard drive?? It was built for external use.