E-29er Bafang 1 KW frame set or frame

Personally I'd get a complete 29er bike and then add the Bafang BB kit.

Bafang makes the newer BBSHD model with a variety of bottom bracket sizes (6 to be exact) : 68, 73, 92, 100, 110, and 120 mm. The most common sizes ordered by vendors is 68mm, 100mm, and 120mm basically because these can fit in all the other sized bottom brackets by spacers and reduces the amount of different kit they have to stock. Of course Bafang produces more of these common sized kits and so you might have to wait longer to get an exact fit kit.

Otherwise there is an alibaba frame for the BBSHD here - https://www.alibaba.com/product-detail/aluminum-alloy-full-suspension-bike-frame_60779086587.html