About 2 months ago after months of research, I bought a 20 foot V-nose Cargo Mate - Blazer trailer in Olympia (manufactured in Oregon) then added a winch from Harbor Freight and mounted the control connection at the back so I didn't have to climb in and out of the window.
There is plenty of room for the Viper and a complete set of tires on a 20 foot, even without the v-nose. This is the same length that at two of the local racers were using for their Viper comp coupes a couple of years back.
I now have added several small cabinets, a rubber-maid hanging system for chairs and the awning and a tire rack as we use it for both my son's quarter midget and my Viper so we try and keep the stuff organized and not on the floor.
In the process of adding electric lights/outlets and determining the best (yet reasonably priced) floor covering. Was going to go install checkered vinyl until to I talked to people at the race track that had it, after 3 years the white is not very bright and if you happen to get water on it, wow is it slick.
Sorry, that may be more than you were looking for...
Let me know if you have any other questions, or I can get some pictures if you need.