I would:
1. Not get a sub with the M60s or the M80s. Unless, of course, you like muddy bass. The M60s and M80s provide more than adequate amount of tight, deep, clear bass. Even better if you have a good amp.
2. Get a tube integrated. The Primaluna Prologue One ($1k) or Two ($1,350). You will get gorgeous warmth, tonality, harmonics, deeper bass, more defined bass, and all the power or loudness you would ever want. Look, I'm not big on suggesting products to people but figured I throw something different to the usual Rotel, NAD, Outlaw, combinations. My opinion is that there are now a couple of tube integrateds that are cheaper or as cheap as a pre/pro combo from brands like Rotel, NAD, etc...
3. Use the above amp with a cheap cd player. In the meantime, save for a big time player. The Primaluna will provide unbelievable detail from the cheapest players. This was my experience.
Do all the above and you will have one sweet system. Do it differently and you will still have one sweet system (due to the M80s). You can't lose!
