You have a good reason to be confident about the whole build, I don't see anything wrong with it. I'd say that you might want to go with DDR2 800 rather than 1000 just for cost purposes, but it will work either way.
I have also not heard anything about that cooler at all, so hopefully it will work well. If you want to go the tried and tested route of coolers, go for the Zalman 9700 or Thermalright Ultra.
Until about two hours ago I had a Thermaltake 120 Ultra Extreme picked out for CPU cooling. Then I did some new digging and found the review for the XIGMATEK. Lighter, less costly, and equal or better performance to the 120 Ultra Extreme.
Well, now I have heard something about the cooler. I also saw it suggested somewhere else, so I guess it is pretty good. Now I can say that it is a solid system, and I'm glad you put in some research before putting in a grab bag of items and waiting for us to suggest things.
*I meant the TrUE, just forgot whether it was Thermalright or Thermaltake. Stupid companies and their really similar names.