What are the pros and cons of using (2) 50 gal. steel drums (restaurant grade) vs. a 250 gal. propane tank. Obviously the cooking surface will be smaller with the drums, but is there a huge difference in heat retention? I have a million other questions, but this is a good place to start. Oh yeah, I have also already acquired the drums, but am having a difficult time finding the propane tank. Thanks for your time.