Ira,
Ira, Ira, Ira.......
I've been lurking here, not posting (could it be because my tear is at a standstill for the last 2 years or so?), and I come across this post. Then I start reminiscing about all your other threads. I must toss in a few pithy jibes here...
Where are you going to put this once it's done? On the side of your house so the neighbors can call the cops on you? Or will you need to rent a storage facility? Aren't you in one of those moderated gated communities? Don't your neighbors already hate you?
What are the chances that this contraption will actually draw the heat through itself as it should? You're talking 3 wood/charcoal, 1 gas? Firebox attachment? How? How will you get the heat/smoke between compartments in a reliable fashion? How much food do you really need to cook? Each one of those Brinkman's could hold a minimum of 9 - 12 full size spares, that alone feeding at least 30 people (with usual appetites and normal allotment of sides). Do you need that kind of room?
If you must do it: Get a couple of Weber Smokey Mountains. Build a nice contraption that will fit through the door of the Crab. The WSMs break down to a reasonable size, transport them in said container (or the back of your car). At full retail for the 2 it will set you back ~$400, if you Craigslist you may be able to find for less (my last one was $35). Set them up next to the Crab, fire them up, use the galley of the tear for the food prep and service. If the food comes out bad you can lock yourself in the tear if need be to get away from the pitchforks and torches.
I get tagged to do parties for friends all through the year. I've got 4 WSMs (and 4 kettles of various sizes, and 3 or 4 other variants). I've done parties for up to 130 people will ease, with the addition of a Cajun Grill (
http://www.cajungrill.com/ ) for finishing purposes. The WSMs can also be used nicely as a Santa Fe style grill....or with long skewers as a churrasco style (your wife will once again think you are a god).
I'll go away now. But hey, thanks for listening.