I regularly sell off equipment I am not using ... I just don't like it cluttering up my closets and storage cabinets. Or my mind... 😀
Anyway: I'm not you so it is hard to recommend what to keep or sell as if I were you. For me, though, it's been about a half year or more since I exposed any film other than Polaroid, and of the digital cameras I haven't already sold off, only the Leica M-D 262 has gotten any real use. The M-D, to me, is special because it's the closest thing in use to a film M that any digital camera can be. All of the shooting benefits of a digital camera with none of the distractions. So, right now, I could easily say "dump everything but your favorite M and your lenses, that's enough for anyone." But I'd recommend upgrading to a newer digital M (M10, M-D, M typ 240, etc) because the M8 and M9 are probably the most fraught cameras Leica has produced in decades.
BTW: That's no reflection on Leica ... it just points out how difficult it was to build a digital version of the M. Remember that as of 2003-2004, Leica was still saying they weren't sure it was even possible. The technology of digital sensors has advanced tremendously since the M8 and M9 ... Far as I'm concerned, the M typ 240 was really the first camera that realized the digital M goal. The typ 262 and M10 go nicely, incrementally, beyond that.