I dunno about chargers and the leaf cells.
But lifep04 (which is safer, and has 4x times as many charge/discharge cycles! and is WIDELY supported) isn't terribly expensive either.
60 ah are like $66. Assuming you are paying ~ $105 per leaf cell * 9 = $945 for 65ah at 67.5v.
GBS cells are
a known quantity. You would need 21 for the same voltage and about the same ah, or $1386. $441 more, but they last 4x as long, so really you would save $2394 over the long haul with lifep04 gbs 60ah cells. Plus you aren't experimenting with leaf cells and can lunch off others experience with lifep04.
GBS Battery : GBS 60Ah LiFePO4 lithium battery
It makes a lot of sense to me given where you are at, but I think I will just grab my bucket of popcorn now
