hegels (190/390) will drive any reasonable speaker (and some unreasonable ones)
the tonality is neutral, with excellent bass control, excellent imaging and very clear midrange and treble... a tiny bit of midrange warmth with neutral (not rolled off not accentuated) treble... but very clear clean transients
they will pair well with many many speakers, so pick speakers whose sound you like and will work well in your room - they will do great with magnepans, better than many other amps, but certainly not limited to those