McIntosh MA9000/MA12000

C2800 and MC462 would get you separates with a tube preamp and solid state stereo amp rated at 450 watts.  I don’t have separates but generally speaking it does everything better when you do.  Are you better off?  That depends on what you want.  It gives you more options to combine different preamps and amps.  Clarity, soundstage, transients, imaging are usually better, wider, deeper, and faster with separates.  If that’s what you want then separates are the way to go.  For $20k If I had the space I’d go with separates.

I have heard the McIntosh MA 12000 on multiple occasions and have even recommended it several times on Audiogon. The bottom line is it sits in the sweet spot of the entire McIntosh product line.

This is a hard question to answer.  It is really owner preference.  I am running all McIntosh separates setup with Tube monoblocks (pair of Mc275) and tube preamp, no subwoofer.  I get a smooth, sweet sound with lots of bass through my Wilson W/P 8.  McIntosh Integrated are well made and have great reviews and reputation.  You cannot go wrong either way.  True separates will cost you more on equipment and cables.  I have separates because I am old school and always wanted separates.  I like all the hardware and the sense of more tube dynamic range.  I also really wanted double the power in my large room, ie. the most tube amp power I could get.  In general, my opinion is that McIntosh tube equipment pairs very well with detailed oriented speakers.  The equipment complements each other and produces sweet music.  Since you already have powered subs, you probably need less power than I did, so, a stereo tube amp or integrated will probably work nicely. You can see my setup through the link in my signature.  Good luck on your search.

I certainly enjoy the blue meters and the house sound that goes with them. I have alot of separates and think you can get more wattage,separation of power transformers autoformers .most of the high end gear has the power suppply for the pre amp in separate chassis for a reason ,less interfearance. 12000 mcintosh. The other plus if you buy used like I do Mac has the best resale value even decades old. Would be nice if you could find an audio club to listen. Enjoy the hunt.

If I had more money, I would go for the C55 + MC462 combo.  I demoed the C2800 + MC462 combo also, and it sounded better than the MC12000, but with much more expensive speakers, so difference could've been due to that.  Either way, both are fantastic