I have my MC200 storage disabled and am using a TwinStore. However I think the the amount of storage needed would be similar.

My FLAC files as ripped by dBpoweramp occupy 369GB
My Sooloos storage occupies 499GB but that includes Sooloos generated MP3s which you can turn off.

I think you'd be OK with an MC200 for a while.

MC200, Twinstore, 808v6/ID41 -> DSP8000SE (+ SB Touch, Sony BDP-3300, SKYHD, legacy cassette player)
2nd system: MC200 analogue out, Linn LP12, SB3 -> Quad 34 -> M60 rosewood
F80 (Rubino Micallizzato)
F80 (Rosso Corsa)