If you are just starting the motor, you could use a 12 volt battery and run the coil off of a 6 volt battery charger. I always use a battery charger in this situation because the voltage stays constant while the starter is pulling a lot of current.
I have the trailer wheels on my 1951 1 Ton. The one thing I would say is that there is only a small amount of space between the 14" drums and the wheels. This works fine for me but I don't carry any loads. This might not be ideal for heat dissipation on the rear drums.
