I got to drive a 16' truck across a few states for FSAE last year. It was a Mitsubishi Fuso, from Enterprise. Had a 2.0L turbodiesel engine, making 160 hp. 6 speed automatic. Didn't think it was too bad. Limited to 72mph, so I ended up getting on the highway and holding the gas pedal to the floor for the next ten…

Breckenridge is pretty close to Denver. You can take the train from Denver to Miami, but it takes three days, and costs $426, according to Amtrak.com. Or, you can fly for $170, and it'll take 4 hours.