I'm a long time owner of Mirage floorstanding speakers, including a pair of M5si's I've had for 16 years. You definitely want both power and current, and large gauge cable going to the woofer inputs. I use a 6-gauge cable run to my bi-wirable M5si's. I'd use *at least* 12-gauge wire with the M1s.
The factory specs for the M1 indicate a sensitivity of 83 dB. This is *low*. You need to aim for the most power and current you can get at your budget, preferably high current amps in the 150-200 wpc neighborhood. You can find used high current, high power amps within your budget from Adcom, Parasound, Rotel, older PS Audio, and--as mentioned--Aragon.
If you're willing to go a bit above budget, you can get a new warranteed pair of 200-watt Outlaw Audio M2200 monoblocks for $700.
The factory specs for the M1 indicate a sensitivity of 83 dB. This is *low*. You need to aim for the most power and current you can get at your budget, preferably high current amps in the 150-200 wpc neighborhood. You can find used high current, high power amps within your budget from Adcom, Parasound, Rotel, older PS Audio, and--as mentioned--Aragon.
If you're willing to go a bit above budget, you can get a new warranteed pair of 200-watt Outlaw Audio M2200 monoblocks for $700.