If one could be addapted. It seems you could pull out the top shelf, mount an assembly inside that would take a rotisserie skewer (like the setup that's on Viking grills- where the rod just sits on mounts on the inside and you can put the meat on the skewer and just drop it in the mounts- motor outside, of course).
As far as what to put on it, I think that every thing remains moister and self marinates on a rotisserie. I would use it for rib roasts, turkeys, tenderloins, leg of lamb and chickens. Obviously it would get more use when you aren't cooking for a ton of people.
I also think you would get a killer brisket if you were just doing one.
Also, there is at least on smoker out there that bases its philosophy on a rotisserie concept: the Genuswine
http://genuswinebbq.com/ss.htmI'm just thinking outside of the box (about the inside of the box) and the FEC100 is such a fine piece of equipment that it has aroused my long dormit Industrial Design instincts (KU, '71)
I also have some ideas on a fire mitigation addition that I will make a prototype of and get a picture up so I can get feedback on its viability.