Scott's been working on a welded trailer to go along with the tub kits and he's come up with a really nice design.
It has a receiver on the front which will allow for multiple tongue options - a standard stubby one, and extra long one for carrying kayaks/canoes/etc, and heavy wall one which will accept a multi-axis coupler.
The frame can be set up with 29" 4 leaf trailer springs, Jeep YJ springs, a torsion axle or an independent air-bag suspension (for those with deeper pockets).
Here's a spy shot of the a prototype frame arriving at Scott's place, of course being transported on his trailer: