What kind of burners are you using? You could probably use that one reg to supply all three burners, as long as you're using a manifold. It's kinda cool to see the flame blast out on high....but be careful not to let the flame blow itself out. I recently souped up my reg from 10 PSI to 20 PSI and found that the burners would go out because the pressure was too high (in so called hi-pressure SQ14 burners). Needless to say, just a minute of unlit propane blasting from the burner could really create a dangerous situation; even in a garage with the door open.
The good news is the reg is 0-60, so it will work with any burner. I wonder though.....what would possibly use 60 PSI??? A furnace?