Hi,
I'd like to that say I thought of this thing myself, but I didn't. The recent America's Test Kitchen email had a link to the La Caja China Roasting Box. You have to check this out....
http://www.lacajachina.com/
You put the pig in a box with a grill full of charcol above it. No flames/starter fumes on the pig! You can raost other stuff on it, too. They have three models.