Why don't you paint the underside first, then bolt on the suspension that you already have, then install the engine/tranny, then mock up the complete car, then pull the front sheet metal/doors off and send it to paint. That way when you get it back from paint, you'll only have to do wiring, interior and trim?
I'm not the expert, but at least that way you could get it off the dolly and get the car into a one piece roller.
BTW: nice project, and I dig the color!