45 amps should be plenty. Pick your favorite flavor... I'm happy with the Powermax Boondockers, no one says bad things about Iotas or Progressive Dynamics. If you search Amazon, note that the lowest-price offerings of the Progressive Dynamics are sometimes the 91xx series that require the optional Charge Wizard dongle to do multi-stage charging... the 92xx series has that built in already.
Il Carriaggio — 1975 Argosy 24 | Il Progetto — 1976 Argosy 28 Center Bath | WBCCI# 15566
He has all of the virtues I dislike and none of the vices I admire. — Sir Winston Churchill