What is better or supply power longer? Two(2) six(6) volt batteries wired in series or two(2) twelve(12) volt batteries wired in series? I am debating which way to go for the longest lasting power as...
Get the 6 volt. Long term you will be better served.
The only downsides are that you have to buy them and replace them in pairs, they weigh more (actually a good thing, but has to be considered), and finding boxes to fit.