you would need some type of vacuum pump to get a suction. depending on the material you might be able to just use a shop vac motor/pump, but with one of those you really have to watch out for heat buildup because it wont take too much.
we made a couple here out of aluminium and on plastic parts it works like a charm. but we did buy a commercial vacuum pump.
the amount of PSI you would need (not sure if a vacuum is gaged in PSI) would depend on the material and how flat it actually is I would imagine.
other than that, the setup you described sounds to be fine.
For the fun of it, I google searched DIY vacuum tables and came up with a crap load of resources.. might want to do that too..