@koryzory I'm not too sure where best to get one nearby but if shipping isn't a huge deal I'd recommend reaching out to one of the 3rd party repair shops in the USA to see if any have a BMS they could send out.
https://www.stokelifeservice.com/
Facebook is usually pretty good for used parts too so if you have an account you might be able to locate one in a local or nearby group.
What's wrong with the current one anyway? Could be a simple fix or something else.