Have you seen the camper-vans they have these days?
Check out the 'Westy:'
Click here for more info.
They are built on an E-250 / E-350 Ford Econoline chassis, so they should be able to tow your 911!
An aquantance of mine has a Westy, and he absolutely loves it! The interior is well designed, and I believe that car is perfect for weekend camping and as a track support vehicle!
-Z-man.