Enclosed Car Trailer Buying Help!

ok guys im in the market to start looking at an enclosed car trailer. It will be my full time storage for the 68 as well as all the tools for the track, etc.

im thinking a 20ft x 8.5 but dont know much about options and brands. i dont need a fancy one with built in generator and etc but one with T bars would be nice.

anybody have a source to look online that they have delt with and are reputable? any other info or things i need to know before looking?

thanks!