Ah, I see. Well, you've got your priorities straight anyway.
Look for a battery from a supplier who credibly claims to use cells from Samsung, Panasonic, LG, Sony, etc. And it should have a full function BMS (battery management system). As 999zip999 suggests, Luna Cycles is a good place to look for a battery meeting these criteria, from a supportive US based retailer, at a reasonable price.
This is to express my gratitude to Justin of Grin Technologies for his extraordinary measures to save this forum for the benefit of all.