For the engine starting battery you want a starting battery your choice of how much you want to pay and how long a warranty. For the coach or house battery ( batteries) you want the deep cycle batteries either 12volt or 6 volts. Be advised that usually the converter will charge the house batteries when plugged into shore power but not charge the starting battery unless you or the other owner installed a trip-l-start unit or something similar to that.
There may be a switch on the dash that will tie the house battery to the start battery so you can start the motorhome (like hooking up jumper cables)
