Bafang conversion kit vendors
I am considering converting a Trek (2008 Fuel EX7) mountain bike with a mid-drive conversion kit.
There appear to be numerous vendors on the internet that sell Bafang (or rebranded Bafang) mid-drive conversion kits (lectriccyles, bafangusadirect, lunacycle, etc), and the prices and availability tend to be all over the place. Also, a lot of them tend to hint that their configurations might exceed street-legal specs. Is there any way to distinguish a reputable vendor from those that might not be? Any prior positive or negative experiences?
My hope is to get something that would allow my wife, with a degenerative knee injury, to get assistance in climbing rather steep and prolonged hills (3000 ft of climbing over 20 miles. She has no interest in going fast, popping wheelies, or any sort of hot-rod-mods.) Any recommendations for configuration are welcome.