So, simply it comes down to having a strong enough amp to run a 4 or 6 ohm speaker. More the 4ohm M80ti.
The sound level of the speakers take care of themselves and balance according to receiver sound selected(5.1, dolby, 2 channel, etc)
On this note a 100 watt @ 8 ohm Denon or Onkyo may stumble if powering the M80ti at louder volumes. What would the minimum power be suggested for the M80ti as mains with VP150 and 2pr SQ8's. Sub to be determined.

M80 VP150 4-QS8 EP600 Monitor Audio S8 NAD T 773 Anthem MCA3 II Hitachi 57" projection