if it were me, id find three 1ohm 1kw amps that have a digital strap to interface all the gains\crossover\signal to each of them. the 20.1 will handle .33 ohms, but id not want to be running that daily. just because im a freak and that would make me nervous lol.
I Think 3 Mx's Would Be Way Better Than The Mags,i Aint Saying Mags Isnt A Super Sub,but The Mx's Look And Sound Awesome,u Talking About Some Extreme Excursion With The Mx's,super Sq,and They Have A 4'' Voicecoil,and The Neo Magnet Structure To Run More Efficent.