Only use a Co2 burner with a glow plug for a sealed room. DO NOT USE A PILOT LIGHT. You can do a search and read about my Sealed Room ill answer any of your questions there. As for how big of burner to buy. I would buy a 8 burner the bigger the better. you want your room to fill up as quickly as possible. Im guessing you are useing a Co2 computer as well. If not you should get one. The Co2 computer will control how much PPM of Co2 is in your room.