>>4035043Any kind of professional field that is purely clinical in nature like that will benefit from purely clinical camera statistics. In fact, you may find that in fields that rely on contract work, better gear gets you more gigs. High megapixel count and good iso performance should be at the top of your list. For anyone else looking for similar advice, this includes document scanning, fine art, commercial product, industrial and real estate and architecture photography. Other genres like portrait, travel and wedding and event photography have lots of wiggle room for subjective tastes and clients are far less picky. Take any kind of advice pertaining to color science and artistic merit with a grain of salt. Image resolution and quality is all that matters to you here.
For you OP, I would consider mirrorless over dslr because shooting speed is not an issue for your use case which is dslr's last advantage over mirrorless and it's not one that I expect to be held forever. Think long term. You may be investing into a mount that will serve you a decade or longer.
NIkon Z7, Sony A7RIV or Canon R5 would be great choices. All are high MP full frames, 45.7, 61 and 45MP respectively. The Nikon is a great budget option with the Sony taking the mid-range price point and Canon obviously the most expensive. All are amazing choices for your field of work. Start watching reviews of them to see how they differ and what each offers. Go to a store, try them out in your hand and how they feel. I would approach this decision as if migrating to a whole new system with the intent to bring no existing glass. I am assuming you're in a country where you can declare work expenses against the year's taxation, so price isn't much of a concern, plus, that is a well paying job.
Good luck OP
