I've looked at those too. The thought I had was using a pop-up that goes in the back of a pickup on my trailer. Reason being you could slip the hulls where the bed rails of a pickup would normally be. I hadn't pulled any numbers, the floor might be too wide to do it, but might not be a big thing for them to make a narrower floor either.
I'm not sure how I'd tie a rack in then....
or, just do something like this, with the pop-up on the front. Whole reason I went with a flatbed in the first place was so a big butt sail box would protect the bottom boat completely from anything the tow vehicle kicks up.
![[Linked Image]](http://www.livinlite.com/images/gallery/sut/18SUT-Open1.jpg)
(edit)- Another thing I've been considering is getting on of the hard side pop up trailers, then just throwing the boat on the roof of that. I've got a feeling those are ridiculously/prohibitively expensive