There are some that have the magnification levels needed, but my experience with the digital scopes, like dino-lite or pro-scope, was not great. The magnification was changed on a dial on the side, and focus was by moving the flexible arm up and down. It appears that there are several models that now have rigid stands with a rack and pinion style focus. Those would probably be okay.
For yeast counting and staining, the issue is that most look like they are setup for incidental light (coming from the side or above, same side as lens). Traditionally, microbiology microscopes used transmitted light (light passing through the subject/ slide). Unless I'm mistaken, a microscope in a brewing lab is for checking cell counts and viability by staining. Both usually on a slide, so the incidental light may cause a glare. Plus then a computer has to be near the wet lab.
My suggestion is for less than the cost of most brewers' rigs to purchase a laboratory grade microscope. Unless you want to take photos of the slides, a digital scope/ camera won't be of much use.
