I live in a townhouse, so unfortunately I can't go solar, but I have out of interest looked at LEAF packs for solar and other projects (ie electric motorbikes).
This YouTube video is just one example:
Search on YouTube for BigBattery LEAF for other similar ones...
BigBattery sells a modular kit for building battery packs from individual LEAF modules, complete with BMS and a custom circuit board for cell balancing and for connecting the cells in parallel and series circuits to create a pack with a specific output voltage.
Seems like a well thought out product.