Fisheye lens options and advice

I like the fisheye look. The circular  fisheye is fun, but really a bit of a novelty so I was thinking about  the other sort. trouble os I don't really know what to look for.

I have a 7d, 10-22, 17-40. 24-105, 70-200, 100-400 and 60 macro.  I have heard about the sigma 10mm, but what else is available?

I mainly do landscape.

Thanks for any thoughts