Have a bake sale and raise money for a steel carport. No matter what cover you get, the house will burn down before you get the thing off your truck.
If you insist, I'd call a company like ADCO up and see what they can do for you. CW advertises custom covers for RVs at about $45/ft. Do the math, and I think you'll find a carport competitively priced, especially when you consider that cover will only last 2 to 3 years.
That being said, I use a cover on my RV because 1) I'm not in a hurry to unwrap, 2) I didn't buy a custom cover, so it only ran me $300, and 3) My neighbors would balk at a metal carport.
Good Luck,
Eric