This is what I do (did before the crash), and when I am installing a new shore power converter/charger, I stay with two suppliers. One is Progressive Dynamics and the other is Iota. I own PD units. As said, the house bank stays good a long time and I add very little water. My clients report the same.
The thing that is missing here is the size (capacity) of your house bank. These new c/cs are vary capable of charging a lead acid battery at too high a rate. Try not to exceed 10% of the 20 hour rate. So, if you have a pair of t-105 or GC-2s, then go with a 40amp.
Your batteries will love you for it.
A lifelong waterman and his bride going dry places for as long as the fuel money lasts.