I would suggest to start with ‘mountainboard’ platform straight away Unless, you want to make ‘wedges’, since usually mountainboard trucks need a bit of an angle to work.
You can also check what @lowGuido , @bullrider12 and some others have done with smaller wheels.
IF you with smaller wheels, something like 5-6inch pneumatics, then it might be okay, if you still use flat deck, I think.
Though, for bigger wheels clearance might be a problem, so you might need longer axles and so on…
Im in a bit of a hurry now but i will try to give more details later on if you are interested.
One more thing to notice is - not always, but usually you will need more energy / bigger battery to make the same distance if you use pneumatic setup. @ lowguido seemed to say he gets pretty similar results but I think he had filled tires, not the pneumatic ones.