OP asked, "What works best and gives you the most for your money"? If you look at it from $/AHs it would be 2 6 v Golf Cart Batteries. I paid $74 apiece for my two Sams Club batteries 9 years ago and they are still going strong, and I dry camp 95% of the time. Don't let them get below 50% too many times keep them charged properly and they will be the lowest cost. I think they will be about $84 today. Costco, and some Walmart's sell these also. If you don't dry camp often or have minimal AH needs you my get by with just one 12v dual purpose battery.