You might look into Green Zone Bikes in Sugar Land, Texas. They have reasonably priced conversion kits. We bought two of the 26-inch kits to install on our new bikes. Living in New York, the spring snows haven't ended yet so we have not put them on. However, the company was very easy to work with and responded very quickly to our questions. In our opinion, it is a good way to get started with e-bikes without a huge investment.
https://www.greenzonebikes.com/