Another semi-modal option is Hydra:

https://github.com/abo-abo/hydra

According to the website

Imagine that you have bound C-c j and C-c k in your config. You want to call C-c j and C-c k in some (arbitrary) sequence. Hydra allows you to:

• Bind your functions in a way that pressing C-c jjkk3j5k is equivalent to pressing C-c j C-c j C-c k C-c k M-3 C-c j M-5 C-c k. Any key other than j or k exits this state.

• Assign a custom hint to this group of functions, so that you know immediately after pressing C-c that you can follow up with j or k.

I haven't used it but it seems interesting.