I wired my trailer for both AC and DC supplies. I have an so cord hanging out the bottom of the trailer to connect to AC power with a transfer switch separating the AC feed from the inverter. If you use any kind of transfer switch type set up, make sure you separate the inverter neutral and the house/generator neutral. The electronics in the inverter may cause GFCI's to trip.
Depending on your load, you could probably run off of an inverter. I can get 12 hours of lights, fan, cell/ipod chargers, tv, and satellite of a small Toyota battery before inverter under voltage alarm goes off. I only fire up the generator for the microwave and air compressor.