Let start by saying that there are no bad DSLRs being made. If you can't take a great shot with one, it's almost never the camera's fault. The DSLR's main purpose is to provide you with the control you need over the image-making process. It also needs to have the performance that will allow you to consistently (key word here) capture images the way you want to, when you want to. For this reason, you may need one model over another, or just an entry-level model if you're not doing anything technically challenging such as low-light sports.
My first thought was whether you even need a DSLR in the first place. The mirrorless cameras from Sony and Fujifilm are so good now that many pros are using them as main or 2nd cameras.
The reason you'd want to stick with a DSLR is for the focusing speed, especially when in continuous focusing mode. If you need to shoot fast-moving subjects such as running people, children, pets, cars, planes, etc..., then you will need to go with a DSLR.
Both mirrorless and DSLRs offer the same level of control such as full manual exposure. Mirrorless systems can be smaller and less obtrusive with the right lens. Because they're much thinner than a DSLR, you can adapt any lens from any brand onto mirrorless cameras such as the Sony Alpha series. Their small size is only an issue when used with large lenses such as a 70-200 f/2.8, 300mm or longer. It just feel awkward to hold a small body/large lens combo as opposed to how a DSLR would feel with the same lens.
Mirrorless cameras have an electronic viewfinder (EVF) that makes it possible to see the exposure prior to taking the shot. With a DSLR, you wait for the camera to process the image (a second or two) and then review the image on your LCD screen, providing that you remember to do so. It just provides a bit of added insurance that you'll always be aware of under/over exposed images.
Depending upon how large you need to print and/or how much you need to crop into your shots, you will need a certain level of resolution. Typically you can divide the maximum resolution of each camera body by 300 to get the largest photo-quality print that can be made from the file. Sony's mirrorless cameras are anywhere from 12MP to 42MP, and DSLRs go from 18MP to 50MP. The trade off here is that the higher the resolution the larger you can print, but the lower the resolution (for the same size of sensor) the better the high-iso performance. This is why the Sony A7S II at 12MP is so much cleaner at ISO 3200 vs the Canon 50MP 5DS R.
As I said earlier, if you're photographing moving subjects, then go with a DSLR over a mirrorless. Since the camera is going to be used in a production environment, I suggest avoiding the entry-level cameras such as the Canon T series and Nikon's D3xxx series. A mid-level body such as the Canon 70D or 80D, Nikon D5xxx or D7xxx series, or the Pentax K-3 II all would be awesome cameras capable of printing to about 16x20 inches.
Not sure what you mean by "high-quality shots." I assume you mean that the images look very clean and sharp. That's mostly due to the lens and not the actual camera itself. A great lens on a cheap entry-level body will produce sharper images than a kit lens on a $5,500 pro DSLR.
To see how sharp each lens is, go to photozone.de. Their sharpness charts use numerical values so it's very easy to see which lens is sharper and by how much. You'll may notice that lenses are not immune to being subject to diminishing returns. As you spend more, you get less of an improvement, which often means having to spend 3x more to get a 10-20% increase in optical quality.