As I am typing on a custom built myself, I have just one thing to mention:
Before installing the RC, I would make sure to spend a little time examining and downloading the latest software
drivers for your motherboard and video card. This can be as simple as visiting the makers websites. After you do that, you can then Google to see if anyone has had any troubles with Windows 7 and your same hardware.
With the system I built - even tho I had one of the latest parts on the market - there were several updates.
My beast installed Windows 7 beta so smooth I thought there was something wrong. I didn't NEED the latest
drivers mind you- and odds are you may not either. But if you are going to start from scratch, I figured at install was the best time to get as up-to-speed as I could get.
Good luck with your new build! It looks to be a performer!