Leaf cells are getting all but impossible, however there are tons of other options. I just built a 48v pack using LG Chem server rack cells, and a 36v using Panasonic 3.7v cells from the Ford C-Max Energi, the 25 Ah.
I just ordered what are advertised as "new" Panasonic 3.7v, 94Ah cells from Ebay at $60.00 per for 14 cells, shipped to my house. I'll let you know what they really are hopefully by the end of this week.
https://www.ebay.com/itm/NEW-Samsung...f/154366457858
The only thing about these cells is I'm thinking I'll probably have to drill and tap for posts on the terminals, even though the seller said I'd just need "screws and busbars".
NMC chemistry is good for golfcarts as they're energy dense so they can handle the aftermarket controllers, etc. I love my 36v pack which I shared a picture of here somewhere.