For the new PC build I am considering using the Antec Sonata III case - I saw a friend's case and I think it looks good and seems good value with its 500W EarthWatts PSU. However his system is a fair bit older (Athlon X2 3000+, ATI X1950Pro, 2 HDDs).
I think that for what I am planning to do at the moment (Phenom II X3 720, 790GX, ATI 4870, 1 HDD) the 500W PSU should work just fine. But how close to the PSU's limits would I be if I added an HDD or two later? And would the PSU place a ceiling on overclocking?