Whoof... I would not recommend doing a full boil inside an apartment if you can possibly avoid it. You're basically putting a gallon or two worth of water into the air. Things will get muggy quite quickly.
Presuming you can't get a natural gas hookup, you'll be restricted to butane burners; propane gives off too much carbon monoxide. Even with a butane ...
As mentioned, BTUs are your primary issues. "Turkey Fryers" are very popular and kick out enough power.
Side concerns would be storage. Gas bottles, burners and pots take up a LOT of space. Keep that in mind then purchasing the items. Gas bottles should not be stored indoors.
Please follow COMMON SENSE and your local rules and regulations regarding the use ...
The difference in LP and NG burners is the jet. Propane use a very small small jet compared to NG. The propane jet can be drilled out to the size of the NG very easily.
Propane burners run from 10-30 PSI, NG is only around 2 PSI.
I would definitely get an adjustable regulator. This gives you stable psi and gas adjustments all ...
Based on having done it myself, you will possibly have a burned, smoky flavor and not in a good way. Whether it's safe to drink depends at least partially on what the bag is made of. If the bag was muslin, it's likely safe. If it was nylon, I'd be more worried.