I WOULD LIKE TO BUILD A RACE TRAILER. IT MUST BE AT LEAST 6'6" INSIDE HIEGHT. DOES ANYONE OUT THERE HAVE PLANS THEY WOULD SELL OR KNOW WHERE I COULD GET THEM? I DON'T WANT TO GO OVER 16' LONG, AND I WANT A RAMP DOOR IN THE REAR AND ONE SIDE DOOR. ALSO, IS IT POSSIBLE TO BUY 4X8 SHEETS OF ALUMINUM? IF SO, HOW MUCH EACH? THANKS IN ADVANCE.