Replacing 2 hot water heaters with 1
Not quite sure what you mean by &quot;showing their age&quot;: electric water heaters either leak or don't leak and work or don't work (mostly). Predicting time of failure is difficult. I have a rental house that has an 80 gallon electric water heater that's probably about 40 years old and working fine.  Others I've had to replace after 15 years.
But getting to your question, yes, consolidating 2 water heaters into one is a good idea and presumably you'd put the new one in the garage, freeing up closet space in the house.
Bear in mind that a heat-pump style water heater will COOL the space it's installed bc it pulls heat from the air.  In FL that may be a good thing! Not so much in the north.
You'll have to do some additional plumbing to install the re-circ pump, depending upon your exact plumbing layout.
You might also want to consider a timer on the re-circ pump.  I have re-circ and a timer in my house and set it so it doesn't run between 11:00 PM and 6:00 AM.