I always have to throw in my two cents on these burner question. I use a Bayou KG-40 . i don't remember the BTUs, maybe around 50-60k. They wereinexpensive (my two were $49 each through Amazon, free shipping, no tax) They are built to support more weight than my 15g keggle filled to the top.
A good burner if you don't want to spend a ton of money but want quality. Having said that, and if I have the throw away cash, I might just check out one of those Blichman burners. Many people rave about them. I doubt it's just because they are justifying the expense.