Do NOT get a Thermaltake PSU over a Silverstone...Silverstone are one of the top makers.
baron, the 680i is NOT the best overclocking C2D mobo. The Biostar 965PT which is 104 bucks has the record of 5ghz on an E6600 with one core disabled. The 680 is only rated as "so good" becuase it can fully support SLI. There are many better overclocking mobos out there for literally half the Price. SLI is NOT worth it as all it does is produce more heat, and take more watts. I never recommend it unless you go two of the best cards right away for bleeding edge it just gives off way too much heat and the amount of watts and amps it requires is too much for the performance. If you must go SLI then the 680i mobo is a good choice however do not think for a minute that it is the "best C2D mobo" becuase it's not. Especially right now with it's bugs a and being so expensive, as well as there are many other boards who overclock just as well.
Dominator ram is UNNEEDED. Pure OVERKILL. With an E6600 to even get a 4ghz overclock (which is usually very hard anyway) you need
DDR2-888 ram...you can get ram for half the price of dominator that will clock higher than that. G.Skill NQ's will do that for 164 bucks for 2GB.
EDIT: DDR2-1066 runs at 533mhz really. DDR2-800 would run at 400mhz. You need to achieve a 1 : 1 ratio on your FSB to MHZ.
So if your ram never went past DDR2-800 (400mhz) then that means the max your E6600 could overclock would get to 400x9=3.6ghz
However I have cheap G.Skill that overclock to DDR2-1130 without a problem. I suggest if your serious about overclocking go to a forum such as overclock.net or Hardforums or the overclockers club to understand more about how it works exactly, or I guess you could ask me.