I have a mixte frame and I think mixtes are great looking bikes.

As for ebikes? Most look a bit strange to me. There are two brands that look great. Faraday and Public Bikes Bionix. The public is in both a diamond and mixte frame. The mixte looks great. The Faraday aims for porter style and has a more traditional step-thru paired with the diamond frame. That might be too girly.

Mixte frames are French unisex bikes. And that might be the way you want to go. It is not as easy to step over as some as they are higher. But they generally have road bike like geometry too.