I have a United Expressline 24' Racer Special. I spec'ed out the trailer just the way I wanted it and am very happy with it.
I usually tow with a 31' Winnebago, which gives us a place to stay at the track. Nothing like taking the garage AND the house along with you.
The downside... 5.5 MPG average, but if you can't afford the gas you can't afford to race either.
For short trips, I pull with an F250 6 speed Powerstroke.
The trailer hardly fazes that truck.