I just don't see that 750W Silverstone not being good enough. I have a Corsair HX620W and it powers everything I have, 1 optical drive, 3 IDE drives, 2 Sata drives, 5 fans, Q6600 @ 3.0GHz, Dual 8800GT's, and two case lights. No issues here with all of that so I just don't see it being the PSU, unless it is just bad or something. Of course that 1000W one will remove all doubt.
"Nothing sucks more than that moment during an argument when you realize you're wrong."