Match diesel with cooling capacity, rear end gearing, tranny ability and overall real towing/hauling capacity. chevy duramax-----Ram diesel and ford diesel. Look at all the years and reviews and match to your needs. good luck
We boondock a lot horse camping. Just go ahead and charge battery every day in evening. We've found the biggest draws on battery are heater and exhaust fans and late nite lites. I would use a regular compact battery charger to charge batteries more...