Cookin' lots o' beans question...

I'm going to be cooking a large quantity of beans for our church's 3rd annual Super Bowl BBQ fundraiser. I use a variation of the Apple Baked bean recipe. Last year I used 2 fish fryers with stock pots but the beans scorched. The year before we only made about 40 pints to sell and we baked them in the oven in large aluminum pans, but the church's oven will only hold one pan at a time. This year we are looking at making about 150 pints, so the oven is the last option.
My question is has anyone used a fish fryer/stock pot like a double boiler so you don't scorch what you are cooking...or Does anyone have any better ideas?
Thanks in advance for any insight!