mcintosh integrated amps

An MA6900 and Some Sonus Faber Cremona Auditors would sound wonderful. Cables?

You are right in looking at tubes. You don't give a budget so I will give a couple options of tube integrateds mated to bookies.

I would get some Focal/JM Lab 1007Be and McIntosh MA2275. They are an incredible match. I have owned lots of gear and I have heard even more and this combo is remarkable.

If that is too expensive, try some JM Lab Electra 906 and a Conrad Johnson CAV50.

These pairings are what I recommend. Note the MA6900 is a solid-state amp and while it sounds sublime, you can get more inner detail and naturalness with MA2275. The tradeoff is reduced power...

It is much too early to talk cables. Use what you currently have until you get the new equipment settled in. Then after a couple months (at least) of listening and speaker placement tweaking, you can start to consider changing some cables to make the final adjustments to the sound. This is how you get maximum benefit from your cable selection.

Arthur