Purchased a 2011 EL XD - Need Batteries

I may be a nut, but while researching how to deal with a controller issue on my 2000 4 seater Gem cart, I came across a fellow that had a super clean 2011 EL XD for sale that needs batteries. I bought the thing for $1400.00 locally here in San Diego. I don’t really have a use for it but am intrigued with the 72 volt system and 7.0hp motor and the flatbed. It only has 1,800 miles. It is rigged with eight 8 volt batteries and one 12 volt which runs the lights and accessories.

I would love to have recommendations on battery purchase. Is it true that there is a conversion available to 12volt batteries? Would that change the performance at all?

If kept the way it is, any recommendation for a good set of batteries at a “somewhat reasonable” price?