Best Of

I'd pick a heat pump water heater, second choice would be a resistive electric water heater (which I am quite sure will last a lot longer than 7-10 years), third choice would be an indirect which has so much installation cost and makes you keep running your boiler all year just to heat a few gallons of water per day, it's a solution that only a plumber could love.

your incoming water temperature is the key to dhw performance as @GroundUp mentioned. The water provider may have that exact number

I had 110 Nobel with 52 degree well water and it worked great for two of us

With 10-1 turndown , it will be fine for the heating load

The Knight has some additional features and I like the heat exchanger better

Perhaps a heat pump water heater could be a good option for dhw?

my bet would be on scaling from hard water, or water hammer. Or both.

That pump is rated to 125 psi.

A lazy hand gauge would capture spikes. 80 psi is about the high side of the pressure. Do you need it that high? Lowering it to 50 or 60 would help all the plumbing components. 80 psi can spikes to over 300 psi with a hammer and spike.

Any application with fast closing solenoids needs water hammer arestors. Maybe one at the end of the supply to the machines. High flow rates and high pressure against a fast acting valve are a big concern.

If you have arrestors they could be damaged

You can get arrestors that go on the individual hose connection, or a large size to cover multiple machines