Audio Research Ref 250s for Magnepan 20.1s?

OK, I'm thinking about taking the plunge into large tube amp, upgrading. Will the ARC Ref 250s have enough power for the Magnepan 20.1 speakers? Anyone using this combo? The Ref 750s seem too far out there for me but I would like to hear if someone has experience with either of these? Right now I have ARC Ref 3 preamp and Ref 8 CD player along with Pass Labs XP25 phonopre, VPI table with dynavector cart, and Pass Labs X600.5s. I have plenty of power but had an eye opening experience with a friend's Cary Audio 60 watt triode stereo amp. Nowhere near the power needed but it had qualities I desire such as midrange bloom and wide soundstage without harsh upper end. It was bass shy but I do have Nola subs. Should I sell the pass 600.5s and get ARC ref 250s? or 750s (god forbid)?