Hello,
Keep your original selection of M50s with a VP100, QS4 & EP350. Your room size requires no more to produce prodigious amounts of volume.
Perhaps use the extra cash on a DSP controlled sub, that’s where you’ll get the biggest bang for your $$$$!

Monitor Audio builds a VERY respected loudspeaker, wonderful equipment! \:\)

Those who have long enjoyed such privileges as we enjoy forget in time that men died to win them.