Good choice of CPU - you'd be a sucker to go for the E6700 or X6800 - they just aren't worth the extra cost, especially if you plan to OC a little.
Don't bother with such expensive fast RAM. Get DDR2-800 (PC2-6400). It can provide a little performance benefit with the processor at stock, or allow you plenty of room for overclocking.
Some numbers:
FSB speed = 266MHz for Core2 (default)
CPU speed = FSB * multiplier (9 for E6600 - 266MHz * 9 = 2.4GHz)
RAM speed = FSB * 2 (DDR) * RAM:FSB ratio
Common ratios are (memory speed relative to 266MHz FSB in brackets): 1:1 (533MHz), 5:4 (667MHz), and 3:2 (800MHz).
From what I've read, running 5:4 actually decreases performance in some cases, while 3:2 can provide some performance benefit. So, without overclocking, the slowest RAM you can use is 533MHz, I wouldn't bother with 667 MHz, and you might like 800MHz.
However, for overclocking, you raise the FSB, which means your RAM will need to run faster too. Usually, with any kind of substantial overclock, ratios above 1:1 are not practical, so I won't bother with them. Anyway, say you want to be able to raise your FSB to 333MHz, causing your E6600 to run at 3GHz. This means your RAM will need to run at 667MHz. for an FSB of 400MHz (up to 3.6GHz for your E6600 - it might be too hot at this speed anyway, unless you employ more exotic cooling) your RAM needs to run at 800MHz.
This is one time when you might want to consider a motherboard that allows you to lower the multiplier on your Core2. As you probably know, the multiplier is locked on Core2, but only from going up. You can lower it on some motherboards, so if you wanted to run a 400MHz FSB, but couldn't get your system cool and stable enough at 3.6GHz, you could lower the multiplier to 8 for 3.2GHz, which should be easily manageable.
Check out this thread for PSU advice:
http://www.xtremesystems.org/forums/showthread.php?t=108088
The PSU you listed is in tier 3 - ok, but you can probably do better for the same price. If you can find a PSU with the capabilities you need in tier 2 or above for the same price, go for it.
I know NCIX has the 700W OCZ GameXStream on right now for comparable a price to your antec ($121.99 after a $25 rebate).