I can keep my 24' warm enough with 2 little 750/1500 watt heaters. Shouldn't need much once u insulate it. I just used the styrofoam sheets from lowes to do mine. Then found a buddy that was stripping a camper and picked up the inverter and fuse box out of it. Then slapped ac in the vent hole. And +2 or 3 on the e track. Had that stuff since it was new. I always run the tires on the track then put a d ring in front and back of the tire then run a strap over it. Don't have to strap to the frame that way.