I don't have a Bionx but I do have an e-bike. Depending on the type of terrain you'd be riding, one extra battery might be enough. At least, should you have some kind of system failure you could still ride the bike as a pedal-only bike. On a paid tour, you'd most likely be staying at motels overnight so you'd be able to recharge your batteries--you'd probably want 2 chargers so you can charge simultaneously. I think most non e-bike owners don't realize that many of us e-bike owners pedal most of the time, at least I do. I use my electric motor to assist me on the hills here in the mountainous NW Rockies. I think it would be fun taking a supported, paid tour on an e-bike. Just be prepared for possible snide comments by other envious tour participants.