So, my Canon EOS 40D stopped working (would turn on & focus, but wouldn't take a photo - 'busy' isn't all that helpful).  I haven't been taking sports photos or anything that really needed the performance of a D-SLR, so I sold my zoom lenses on Trademe and I bought a compact high-zoom camera to handle the stuff that my phone couldn't do.

What do you know, after 8 years the WRC is coming to NZ again!

Well, what do I do now? Before September 2020 I'd like to have a suitable camera for taking photos of rally cars sliding through corners.  I'm now thinking about cameras that are fast to respond, focus really quickly and take good images.  I'm starting from scratch, so I can go with Canon, Nikon, Fujifilm, Sony or whoever.

I'd really love to go with a weather sealed zoom lens that both zooms & focuses internally.  I would prefer if it didn't pump air in & out as it zooms.  My previous lens used to pump air and consequently it did get dust inside it.

I'm thinking that maybe the future is mirrorless rather than SLR, all the brands are making mirrorless cameras with interchangeable lenses these days.  I'm not impressed with Canon going to two separate mounts for their mirrorless cameras, this means that an EOS-M mount camera and lenses won't easily lead on to EOS-R mount cameras in the future.  I am very much aware of buying into an ecosystem meaning that there will be a resistance to change in the future, so I don't want to buy into the wrong ecosystem.

So far I've researched a bunch and looked into Canon, Nikon, Fujifilm & Sony.  Here is what I've been looking at and my thinking:

Canon EOS M6 Mk II - This looks like a great camera, maybe this is the one I should buy!  Wait, the lenses are EOS-M mount and I would be locked out of the EOS-R cameras.  The lenses that appeal most right now are actually the EOS-R mount lenses that I wouldn't be able to use with this camera.

Canon EOS-R - This is more expensive than the M6 Mk II, but it would take the good lenses, I can't see the lens that I want though. 

Nikon Z 6 - This looks like it would be a better sports camera than the EOS-R.  I can't see the right lens available though.  Without the right lens this can't be considered.

Sony Alpha a7 Mk III - Sony make a nice lens that would work well and this camera can shoot 10fps.  It would be pretty cool to own a FF camera.  I see an a7R MkIV, I wonder when an a7 MkIV would be likely?  A newer improved version of this camera would definitely be up for consideration.

Sony a6600 - This is a fast shooting camera with a smaller sensor but can take the same lenses as the FF cameras.

The Sony FE 70-200mm f/4.0 G OSS Lens - this looks like a really nice lens, probably the one to get if I went with a Sony camera.  I can't see a Nikon equivalent for the Z mount.  Canon don't seem to make an equivalent either.  With Canon or Nikon I'd have to get the lens adaptor and buy the SLR lens, this takes away the point of going with the newer mirrorless system, to some degree at least.  In some ways this is the lens I want to buy, so I'm considering the camera to go with it.

Thoughts?  Opinions?  Things to consider?