Something else to consider. You are used to a prosumer camera. It sounds like you are going to be making money with your photography. It also sounds like you don't have much in the way of older DX lenses.
Assuming that, I would suggest you look at a mirrorless camera in the prosumer line. You will have to stretch a bit beyond your stated budget, but I think you may be happier, and less expensive in the long run. Right now the Nikon Z5 is on sale for $1000. For an extra $414- $434, you can get a like new or excellent condition Z 24-70 F4 S-line (professional line) lens.
The Z5 is a full frame sensor 24 megapixel sensor camera. It has dual SD card slots for backup memory on important shoots. The electronic viewfinder makes identifying highlight clipping easy. Both the camera and the S-line lenses are weather sealed to protect against moisture and dust. While the Z 24-70 F4 is not quite the lens that the Z24-70 F2.8 is, a good used 2.8 will run you close to $2000. The F4 is a very good lens, robust and extremely sharp, with fast, quiet AF.
Nikon, and, I believe, all the other camera manufacturers are making the transition to mirrorless and away from DSLR cameras. Nikon has already announced they will no longer release any new models in the DSLR line. They continue to manufacture DSLR cameras and lenses, but have ceased R&D on them. I expect current models to be gradually dropped from their manufacturing line as time goes on.
There are many advantages to the mirrorless cameras, and now might be a good time for you to make the switch. FYI, if you have some full frame Nikon lenses, they can be used with the Z5 using an FTZ adapter.
