I've got a 6' wide x 12' long x 7' tall enclosed trailer that I haul my Road King Classic in. Except for a little walk around space, it's pretty much full when the bike's in there. There is a little space at the rear once the bike is in place and some at the nose. You can go from there to extrapolate the dimensions you need. I would suggest you go, with your bike and golf cart, to a local place that sells trailers and try them out. Get one that is wide enough to walk around your equipment inside so you can strap it down easier....plus, you might be able to see it in the mirror when towing....I can't see mine unless I turn on the backup camera. I would suggest that you get the flush-mount floor tie downs and put more of them than you think you'll need. You'll also need a front wheel chock for the bike mounted to the floor or at least setup so you can put it in and remove it. Get a V-nose or rounded nose trailer....they pull better and you have a little extra room for "stuff" in the nose area.
Hope that helps!
