Here are my options (that I know of):
Add the Burley Moose Rack and Kazoo on the back, or the recumbent trailer bike or, I suppose, slap a Bobike Maxi back there and all is well.
Nothing else required; this is a complete solution.
Obviously, there's some sort of Xtracycle solution, but if you want to tell the cult to go, you know, there's always this option:
I haven't found a US distributor for any of these here. I've sent email to Roland directly and to Harris Cyclery re: the Roland, on the off chance someone wants to bite and help me out. Otherwise, I'm going to be spending some time on the phone to Belmont seeing if I can wave enough money at them to import one of these. If Belmont fails me, it's going to be some across-the-pond discussion about how to import something myself. It can be done; I've done it before. Just not with anything this large and complex.