Benchmark or McIntosh....

Between the brain and the heart, heart always wins in the end. Save yourself some grief and go with Mac. 

Maybe a Coda #16 with meters?

If the main goal is to drive the monitors you have harder, squeeze more performance out to try and keep up with the rest of your system, sound signature aside, I’d roll with the Mac’s.  If your heart is set on sticking with your current speakers, I’d also look at some other brands, amps.  Krell would come to mind, Parasound is another, brands known to really drive speakers, it’s not just about watts when it comes to how well an Amp drives a speaker, certain brands, designs will drive and control speakers with better results than others.  Mac is one of the brands that routinely is praised for punching far above the wattage rating with most of their models being able to drive the vast majority of speakers to their potential.  The flip side is if you aren’t a fan of their sound signature, it won’t matter that they can drive the speakers.

Don’t sleep on the fact that Mac’s hold their value, you could likely buy used, try them out and if you don’t like them, sell them with little loss, risk.  There are also some online dealers, not many for Mac’s that offer a trial period regardless of brand, you could take advantage of the trial period. 

Um,

How big is your room?

Size matters.😁