Sure, not criticizing your decision, just wondering what you were looking into. You're correct if you want to keep the large heated bed heating up quickly, 24V is required and that rules out the least expensive and longest standing board - RAMPS 1.4 in its stock config. The modifications to run the bed at 24V and keep the rest of the system at 12V are pretty easy, but you're into replacing your fan and heater with 12V then too. I think you'll see most RigidBot owners go with a RUMBA (12-35V) or Rambo (12-24V) boards and stick with 24V operation. As you say, the conversions will get easier as more people do them.
The LCD nut was just cracked today for the first time, and I suspect you'll see a lot of people going that route as the IAP LCD doesn't appear to offer anything but a higher price tag and print-from-USB (another backer requested/demanded feature).
Good look with your chosen printer. Hope we'll see you back some day!