We just replaced the Eno on our A54 with an Force 10 4-burner. We had the same problem that the width of the cavity is about 60 cm and marine stoves seem to hover aroud the 50 cm wide mark. The Force 10 is 52, so I placed two filler pieces of wood left and right. The original stove was modified by Amel from the looks of it to have the gimbal points at the burner level instead of at the level of the top of the oven. I don’t know why they did that. I could not find a gimballed stove aroud 60 cm wide, Force10 has a wider one but that is about 70 cm wide.
I’ve looked for other stoves as well. There is GN-Espace, a UK brand, very nice, very expensive. Most other stuff I could find is pretty poor from build quality, even Force 10 is not what they used to be since they were bought by Eno (still better then Eno though). But at least they still carry the clever mechnism for the oven door and they are reasonally easy to clean.
In the end you pay crazy money for a stove that has much less build quality then a domestic stove. Things like self cleaning oven walls and so are completely unknown in sailboat stoves.
Good luck hunting for your new stove!