The most stable trikes are the recumbent "tadpole" trikes.
If you are young and flexible, that is a very good thing.
However, you are also mighty low. It gives you a different view looking up at cars. Some people like to have rear flags for visibility.
Anything can get an electric motor put on it. But, they aren't designed for speeding along at 50 MPH. Think 20 MPH.