Kate,
I will probably go with a Smart DC-DC charger - Victron has a nice 30 AMP unit; they allow you to apply difference charge profiles to the house bank that are different from the starter.
So, this would replace the Blue Sea ACR? functionality - I don't believe the Blue Sea ACR does different charge profiles.
Supposedly, some of the new AC based battery chargers coming out will also include this functionality: they basically have mulltiple chargers in one unit for multiple battery banks and also couple directly to the alternator to act as a smart voltage regulator using the charger profiles assigned. Also would like to be able to take advantage of LITHIUM Phosphate battery technology at some point - prices seem to be coming down.
Daryl
Daryl Clark