Mcintosh sound

If you're planning on driving your Apogees, then you'd have to choose the 6900 which has Autoformer outputs and can drive loads down to 2 ohms. You would also have to make use of the built-in MM phonostage to justify the added expense of that feature. Ditto the equalizer. Ditto the power meters.

Keep in mind that a system's sonic signature or character is 85% a result of the amp/speaker combo. The preamp's main job is to direct traffic and otherwise keep QUIET! Therefore. I suggest auditioning various amps with your Slants using your existing preamp and phono preamp for now. Then slowly upgrade those as you can.

I don't dislike (the idea of) integrated amps, but unless you're contemplating a smaller unit for the bedroom or the office, you could be investing a lot of money in a component that would limit your flexibility, forcing you to throw the baby out with the bathwater in order to make a future upgrade.
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You know I don't think the integrated is such a bad idea. The lowest prices you are likely to find are for those. In addition you won't have a problem match pre to power amps fidelity. I have contemplated the same but enDed up with a complete extravagance. I have the smallest power amp they made in the 70s called the MC2505 all of 50 wpc but it has variable gain which in practice work as attenuators i.e. with one source it's like an integrated but dual mono. The sound is I think a bit on the wieghty side almost indelicate and above all authoritative and functional. I keep the runt of the litter to power only my Klipsch Speakers a very synergistic combination indeed but I have my main systems using JM/Focals and Von Schweickerts. So it is a luxury.
The little amp feels like and behaves like an amp twice it's strength and yes it has bass but not the Krell iron fisted bass just no doubt if you have a big woofer these amps welcome them not shirk them.
I echo getting the autoformers for panel speakers not sure if it has the transparency you want with an anti meltdown circuitry. Never tested anything other than cones and domes. still this pugnascious amp succumbed to the previous owners playing too hard and took out some strength on one side somehow a very unusual situation for an amp that exudes an unbreakable air.

Warm, lush, enjoyable, bloomy, not neutral.

Thanks so far for all of your subjective opinions, my Slants drive easily and don't run impedence too low (so that's a good thing!). I easily agree that combos all sound different that's why I search for others that have knowledge, my front end is strictly ARC CD 3 (which is fantastic). I'e done some room tuning and upgraded the PCs (Locus Designs) and have the Slants bi-wired from Grover Huffman, plus I pay very close attention to vibration control. I listen to my music at low volumns and as everyone enjoy the biggest stage I get acheive but....don't want to go back to seperates due to getting carried away with the uograde bug
I posed this question in the speaker fourm but didn't get responces and need some help to evaluate as I also thought of NAD, and maybe MF or Marantz, but looking at a company as well established as Mac and AR also looks to sound good as well. When I change I don't want to have to do it again so the better informed I am the more it helps.

I have had mcintosh Pre-amps and amps for years. I feel that you really can't beat the overall value of the amplifiers or their pre-pros. The magnetic switching promises many years of trouble free service. As far as sound goes. There maybe better, there are definetley worse.
I would sum up the amp sound as a warmer tubelike sound that extends through the complete range of frequencies. I get a very good impact on music that requires it and a the soft soothing sounds as well. I know a few people (BW) that just plain don't like the sound, but obviously a business that has been around since 1949 can't be doing everything wrong. Also one of the strongest re-sale values out there. I did just add an Audio Research LS26 pre map and it seems to be developing a very good harmonic synerygy
that I was skepitcal of at purchase time. I would say that you won't be disapointed and if buyinng used and disatisfied, you should do fine on the resale.