Need Professional opinion on which DSLR for Videos and Stills.

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Hello all I am new here.
DSLR's have only 29m.54s in MP4 but can be extended using MOV.
I was interested initially in the Nikon 5600 but having researched the specs found that the Canon 80D was dust proof but similar in specs.
Then I read about the Panasonic Lumix DC-GH5S, that records to 4K recordings with 60 frames per second and records until the battery runs out. However I read that this is not You Tube friendly, as they require 1080p. I think it is only 10.28MP. Now I think it is too expensive as I was scammed last week of $900 when buying the Canon. Maybe there is a positive there as maybe I was buying the wrong camera.
Reason for need: To capture video for an Equine Hoof Chat Group, where (don't read if your squeamish), where we dissect cadaver hooves to ascertain the cause of lameness due to barefoot trimming methods. To take stills .jpg for photo comparisons. (Guess I will never win a photo competition.)Canon Dissection.jpg
Nikon has a cashback on at the moment until the 31st October, so that is tempting to recoup some losses.
Can you tell me the best place to purchase (it will have to be online as I live out in the bush) with your recommendation.
I really appreciate any advice and thank you in advance.
Many Thanks