Personally I'd go with an enclosed trailer with a ramp door. Towing a trailer is no issue and the bike would be safe from weather and road debris.
Second option (the one I chose) and much cheaper is an open flatbed trailer such as the 5.5x10 wood decked trailer @ Tractor Supply. This size trailer has a well built designed frame and 15" wheels which was important to me. They sometimes have a sale so watch for that. There are smaller ones for less money but I found this size to be the most versatile for bikes and fits my golf car with a rear seat & foot step where an 8 foot long wouldn't. The smaller trailers are flimsy when compared to the 5.5x10 also.
http://www.tractorsupply.com/tsc/cat...ailer/trailers
And third option is something like an Idaho Tote or the like. They're expensive but very convenient since there is no worries backing. Unlike a trailer, the platform is rigid side to side and has swivel wheels that turn like casters on a shopping cart.
http://www.idahotote.com/pricing/
There are other companies out there making them for less money too. Try google searching " swivel wheel trailer ". There is also a bunch of YouTube videos on the subject.
Goodluck.