You stole my idea!!, LOL I was thinking about doing the same thing but I was going to use the speed control and motor out of an old electric lawnmower I have around, Im not sure if the motor will be strong enough now that I see the size of the one you used.
Anyway here is my trailer almost complete. I bought it used but nothing was really done to it on the inside, It is alot more work than I ever expected.
I have 12 volt power in the back for charging and to run the lights inside, a 2000 watt power inverter in case I dont want to start the gen up and I have a Honda 1000 watt generator to run the refrigerator