when i was searching a few years ago I couldn't find anything with the quality of the wrangler or pecos for an offset smoker for around $500. Keep in mind you will most likely need to make a few mods (see my pictures and posts earlier in this thread) to get it where it needs to be, so take that into account. I like that the pecos has the stack exhaust at grate level, is thicker metal and has a large firebox and big wheels.
I still had to:
add steel plates to distribute heat evenly
add gasket seal to both lids
make my own charcoal basket (don't really use anymore, now I remove the grates too from fire box)
taller smoke stack
An offset smoker is more work than any other type of smoker, but it really really makes it fun and worth it when you get it right.
If you really need a ton of cooking area and don't want to have to make mods, then consider stepping it up a level (lang smokers, meadow creek, yoder). They offer trailer mounted smokers and you shouldn't have to do much, but thats a BIG UPGRADE IN PRICE
most of us can't afford them big boys or don't really need something that large.