I've posted pictures of my home made trailer for my AI and various other floating crafts... in the "Transporting Kayaks abd bikes." thread (http://www.hobiecat.com/community/viewtopic.php?t=5658&highlight=trailer
-- sorry for the typo!).
There are other ideas for trailers on the various forums, such as "A Family of Kayaks" (http://www.hobiecat.com/community/viewtopic.php?t=5609&highlight=trailer
You definitely don't want to store your AI on skinny rollers with the amas attached. This would be a sure way to dent the hull. When transporting kayaks, it is best to set them upside down or on their side. If you want to store them upside up, then make sure they rest on a flat surface to spread the weight.
As I was working on designing my trailer, I left my AI sitting on two rollers (1" dia) for an extended week end. When I came back, there were two noticeable dents in the hull. Wider rollers with a larger bearing surface would not leave such a dent, but the bottom of these kayaks are designed to be supported by water, not by a couple of rods.
If you want to store your kayak upside up, I recommend that you rest them on a flat surface or on "fat" rollers. Also, disassemble the akas and amas as they are not designed to bounce up and down on the freeway if they are extended out, or to support the whole hull weight for extended period of time if they are retracted.
Note: I went to Seattle boat show last week-end and Doug Skidmore, Hobie's president, mentioned that Hobie will be coming out with a trailer for the AI with a cradle designed to transport the AI with amas attached. Worth watching out for.