The loads are going to be several computers... no motors and by several, I mean a couple hundred.

What I was getting at was, if I treat the panel like a 208/3ph and run a separate neutral to break each leg down to a 120v circuit, would that allow me to get away with a smaller transformer?

In the end, I need 400amps @ 120v and I want to know if a 75KVA will suffice.

Thanks guys!