Checked out your suggestions and others that also fell into the Hi Recovery category using AO Smith’s slick “Find the Right Water Heater” selector feature.
Total of nine heaters popped up using parameters that suit our family. Least expensive was 50 Gal @ $600 on-line cost (Supply House andor Home Perfect web sites) with operating cost of $241yr. The highest cost is the PCG-75 @ $876 with operating cost of $291yr. All others cost fell in between save for Vertx model @ $1,600.
Of course, PCG-75 blows all the others away in how many back to back showers, showers taken at the same time and gallons available to fill a tub in ten minutes.
The PCG-75 has two Mag anodes (primary and hot water feed) for a 106 yr warranty. Right now leaning towards the PCG-75 assuming the height dimensions work for existing venting.
Also thinking about installing your curve tube and ball valve into the unit before hand.
Thoughts, comments further suggestions welcomed.