I think you will want more amps on the 12v rail for that 8800GTS. I think 'they' recommend 26amps and that PSU only has 24. Thats some expensive products to be trusting to a very low quality PSU.
An 8800 GTS requires a minimum of 400W PSU with minimum of 26A on the +12V rail.
What part of minimum don't you understand?