jerryg123,
I also have 3 dedicated lines. One for the Niagara 7000 which powers my main stereo system. Another line (Niagara 1200) for my subs and the last one (Niagara 1000) for my home theater equipment. I have had all on the one Niagara 7000 with no problem. But it is more convenient using the multiple dedicated outlets.
I’m not sure what type of amps you have but my 350 watt per channel tube mono blocks and my JL Audio F-113's had more dynamics plugged into the Niagara equipment.
ozzy