What is a great preamp match with the Mcintosh MC754 amplifier?

I'd recommend the Mac C712 or C15 pre's for your amp, both  are good, and have remote control. However, you will have to cough up a bit more coin for them on the used market.

Mac + Mac, the way I’d go.

Not a lot of those made, 15-1600 something like that.

No Macs for 500.00, maybe a logo... ;-)

If you can find a Parasound Zpre3. I have one they sound quite good with my MC275 CE. I have older Mac Valve units, MC225,240,275 all sound quit good, with the parasound, and planar based speakers.

It has remote, sub out, all kinds of onboard goodies..
Check one out.. I got mine for 295.00 it was a bargain from what I was told. After I got it, I knew it was.
Great unit.. I'd pay 500.00 no problem at all.

Regards

Just in general,  I would want to mate a Mac amp with a Mac pre-amp.  Don't know enough about that model to say exactly which one, but I'm sure there are pre-amps by Mac designed specifically to work with that amp hopefully with the features you want.   Features are a big part of selecting a pre-amp.

My first foray into high(er) end audio was with a 754...loved it! If you increase your budget just slightly, you might be able to find a used Aric Audio preamp. It is a completely hand made, tube based piece and it will make beautiful music with your 754's. Enjoy!