Looking for advice on a core i7 build

[Vela]

Hi there

I'm looking to build an mATX core i7 920 DO system overclocked to 3.5 to 4.0 ghz. I've built my own pc before but I've never done any overclocking, I figure getting a parts list put together is a good start. Here's what I have so far.

Asus rampage II gene
core i7 920 DO stepping
Corsair XMS3 TR3X6G1600C9 6GB DDR3 3X2GB DDR3-1600 CL 9-9-9-24
Intel X25-M 80GB 34NM Postville 2.5IN SSD SATA
Thermalright Ultra 120 Extreme 1366RT Heatpipe Cooler
Seagate Barracuda 7200.12 1TB
Antec mini p180(middle hd cage removed, 120mm front fan installed)
Antec TPQ 850w
HD 5870 x2(most likely)
Arctic Silver 5 HIGH-DENSITY Polysynthetic Silver Thermal Compound
Windows 7

I'm unsure about the ram and cpu cooler I chose, will they be sufficient to get the cpu to 3.5ghz to 4.0ghz? The other thing is the PSU; I will likely upgrade down the road by doubling the amount of memory and getting a second 5870 x2, will 850w be enough? Or should I go for the TPQ 1000w instead?

Not sure about the ssd, I may or may not get, depends on my money situation at the time, but if I don't get it, I'll probably just use the 1tb drive, will that be a problem for OC'ing?

I'll worry about how to overclock it later, I just want to make sure I'm buying the proper hardware to do it.

[schvidah]

In regards to the SSD, I just built an i7 rig (using the new i7 860) and put a Corsair P128 (CMFSSD-128GBG2D) 2.5" 128GB SATA II MLC Internal Solid state disk (SSD) into it. I am running Windows 7. This drive is fast, runs well and I love it. I will say that the 128GB drive is already about half full with Windows 7, Crysis, and Batman Arkham Asylum on it as well as just a few other various programs. You might want to look at something a little larger than 80GB is the point.

As for your standard HD, I think most people here recommend the WD caviar Black as the best HD of the moment.

I do not present myself as an expert, just commenting on what worked for me.