Making a computer. Need Advice?

for the PSU I have a Antec 1000 watt. but that might be ok depending how much your into gaming. I'd say to have two hard drives. one to hold OS and such, and the second one to hold your music,movies, and ghost your PC once after you've installed all your stuf incase something happens. I use Acronis True Image Home. for OS,I got XP cuz I know XP supports most current stuff,but I got Windows 7 as a second OS. I hope this helps.