Charging a Battery Bank

Well, a step in the right direction anyway. I have a friend at our local County Highway Department (Supervisor at County Highway and fellow camping enthusiast)and I was discussing with him that I'm looking to buy 6v batteries to replace the one 12v Marine/RV battery that I have. He said he would call the Interstate guy they deal with and would check prices/availability of 6v Interstate batteries. I mentioned that I would prefer Trojan batteries but there are no local dealers. He called me back today and told me the Interstate guy said he sold Trojan batteries. My friend said the Interstate guy told him there was some affiliation between the two companies but wasn't sure if Trojan bought Interstate or Interstate bought Trojan or there was some other affiliation between the two companies. In any event, He gave me a price of $116 for the T-105 Wet Cell batteries so I asked him to get me prices for the Reliant T-105 AGM's. When I get those prices, I will make my battery purchase.