The Sebart Miss Wind is a nice electric Bipe. It's a 50e class and uses 6S LiPo Packs.

It's a pattern plane that can 3D so you can set it up from mild to almost wild.

The Great Planes Reactor 61 would also be a good choice.

The Super Skybolt exhibits exactly the flying qualities you are seeking. It's a fantastic plane but is not really ideal for electric conversion.

Personally, if you are truly serious about progressing to a Beast 100cc then i would forget about electric for this "transition" choice and go with a small gas engine so you can get a feel for them too. A 100cc gasser is not the ideal way to learn about gas engines.

A Skybolt with an NGH 17cc or DLE 20 would be a good stepping stone.

Come to think of it, The Reactor .61 is a GP/EP model so you could start off with electric and convert it to gas later on. The NGH would fit well. I've seen DLE 20's crammed in there but it's ugly.