Shok -
Your budget and brand preferences will obviously be big factors in your ulitmate choice, however, the latest style of Motor Cycle Trailers with their lower profile, are also gaining popularity for our hobby application.
Below is a Link to the Pace site and their upper end M/C unit. I second Bob's suggestion on the larger Front Curbside Door. IMHO, I also recommend a Tandem Axle vs Single because it's a smoother ride for the precious cargo inside. In the event you decide to sell it later on, I also believe that the Ramp Door will increase the potential buyer pool and result in a higher return on your original investment. Again, just my 2CW.
http://www.paceamerican.com/index.cf...roducts_legacy
Good luck.