Speakers for Mc240

I’m a fan of my McIntosh MX110z as a preamp (I only use the line level of the pre as I have a separate phono and MR67) - it was designed for the 240 so synergy is good. Devore Fidelity speakers pair well also pretty much any Klipsch heritage series.  You could get some vintage heresy’s and upgrade the crossovers and the tweeters (Crites are drop-ins) and you would have a fabulous sounding system.

positive feedback re: vintage McIntosh tube equipment

That is why I tried an mx110z tube tuner preamp. After a year I had it overhauled by Audio Classics here in USA. New gold plated RCA jacks my favorite upgrade.

a few McIntosh classic tube preamps had tuners, it is a terrific sounding tuner, you will want a dedicated FM antenna (IF you want to use the tuner).

If you get a model with a tuner, it allows you to sell the MR67 Tuner (or use it elsewhere), and eliminates a component and pair of interconnects. The McIntosh Mode switch and features are wonderful.

https://www.audiogon.com/systems/11422

You say you have phono solved, however when you compare, you might love the MM Phono in the mx110z (it has two), (or other vintage tube preamp).

I use a SUT for my MC with PASS for MM so I can continue to use the mx110z's MM RIAA. You may have seen it, I run 3 tonearms into a SUT with 3 inputs, only 1 cable needed out to the mx110z. I just changed 2 of the 3 arms

I add a Chase RLC-1 Remote Line Controller to keep Vintage Tube sound and features, but have remote volume and remote balance to refine the imaging of any track.

hifishark mx110z listings

Chase RLC-1 New Open Box

You need the remote control for the Chase, there are no controls on the unit. I like to keep things minimum, but no one can tell if it is in or out of line, and I am not living without remote volume or remote balance just to satisfy the idea of simple. You can always use it thru an optional tape or processor loop, that's how I use it in this legacy component's system

Speakers you say, I missed that, I went straight to what preamp.

I find 40 wpc not enough for 90 db sensitivity for a main system, so you might get a lot of people recommending Klipsch Horns, Cornwall, .....

however if a secondary, like my office, or never going for big powerful bass, I’m actually quite happy using a small tube luxman SQ-N150 (it delivers beyond it’s 10 wpc/6 ohm rating) to drive a pair of restored AR-2ax which are 90 db, 3 way, 10" woofer, enough that I don’t add a sub. I highly recommend AR-2ax, they have no vents, and actually fit on a bookshelf, and have a pair of level controls to adjust in any listening space.

https://www.audiogon.com/systems/10092

In my case, for Phono, the Luxman has built-in Phono, MM or MC, (single 0.33mv/100 ohm setting), So far, I have only used MM in my office.

Look into an AVA FET-Valve CFR all tube line preamp. $2299.00

For speakers, the Fritz Carbon 7 SE have a smooth impedance curve and are a perfect match with any tube amp. $2950.00 per pair and you’ll want some sturdy 24” stands.