rackmount DC power inverters?

I have no idea if this is on or off topic (apolgies if the latter). Right now we're running 48 1u servers in a cabinet off AC. We're considering switching to DC power supplies with the hope that any cost increase in the power supply and rectifier would be more than offset by the cost savings in electrical and cooling. So I'm looking for a rack mountable DC rectifier but since I've never shopped for one, I don't know "good" ones. Any help would be great. -- matthew zeier - "But if you only have love for your own race, Then you only leave space to discriminate, And to discriminate only generates hate." - BEP