For a gaming rig based around your components I would....
Uprate the PSU to 800W minimum, 80+ & SLI certified. This will allow for an SLi upgrade in the future without havng to replace the PSU
Put two 250GB hard drives in RAID 0, then have a larger backup drive for file storage.
Pick and chose your CPU cooler. Spend a little more now and give yourself some overhead to overclock your newly built beast!