What are your plans for the boat? Do you think you'll be towing it around to different waterways, or is it more likely that you'll only use the tow vehicle to launch the boat at the beginning of the season, and pull it out at the end? If it's the latter, then it may make more sense to simply pay someone to do it for you, rather than invest a lot of $$$$$$$$'s in a big rig that will cost you a lot in fuel.