depends on “how different” you want to go, there’s a couple steps beyond the ergo mech – a steno keyboard still requires good use of both hands, but a one-handed chording keyboard would be the next step
your words-per-minute WILL go down (steno keyboards get their speed from the dictionary software (Plover) rather than any fanciness in the firmware)EDIT: quick list of EU shops- Keycapsss