You're making too big of a deal out of this.
ASUS P5B Deluxe.
A motherboard that knows no [practical] limits.
G.Skill 2GB DDR2-800.
Memory to let your processor hit 4.0Ghz, and then some. NOTE: I will be shocked if the E6600 hits 4.0Ghz.
Some of the best air cooling around without going for a monster tower in your case.
There, that wasn't so hard, eh? No other parts will affect the processor. I suppose Case cooling could be a factor. But other than that, those parts will take your processor as far as its going to go on air cooling. The overclocking limits are more often determined by the cooling though, not the hardware. If you want to get a faster clockspeed than what those parts will provide, then invest in some custom watercooling. Phase-change would take it even farther, but the performance increase would not be worth the price.
Talk about making mountains out of molehills. We designers on the forum specialize in maxing out the capabilities of hardware as best as we can without going over-budget. To us, what you have proposed is nothing special; it happens everyday in every single build that we design. No one designs (or is atleast supposed to design) a computer that is not the best that a certain amount of money will buy.