The problem with using a utility trailer as a base is by design their floors are too low to put holding tanks under. Myself, I will not consider anything other than a 4 season capable camper as I do not like to be limited to fair weather camping. With a utility trailer, this would mean having to mount the tanks inside and the toilet having to be mounted on top of the black tank. Not a very ergonomic situation. You are really looking at having to build a second floor inside the trailer to provide space to run utilities under thus cutting into headroom. I really think you should reconsider and look into toy haulers. 10K should get you into an older used one.
