In a few minutes of searching I found these sites. I am not sure about the camper but these sites look like they would be willing to get you one that fit with the camper.
The first one is based in Michigan and the second in Cali...
good luck...
www.carcovers.com
www.calcarcover.com/default.asp?flash=1
I saw your website... great looking 4Runner, Have you written up(instructions) anything for the mods. ( I would reccomend you for the mod-of the month) I really like those Mag-lite clips. (I wonder if it can be done with Tundra, Sequoia ...etc...
You also might be able to sell your spair parts here a little easier...