We are a family with 2 kids aged 9 and 11. We are all getting into cycling, but we live up 5km dirt track that is all uphill on the way home - too much for us to cycle up. Rather than have to drive the bikes home, we want to get e bikes. Any recommendations for bikes for the kids? And for first time adult bikes too. They need to be able to handle a steep track, but be economical too. Thanks for any advice.