The lighting for me has been simple stuff. The smaller
AmScope stereo microscope I have has an adjustable led light which makes my life easier. For the bigger Trinocular stereo microscope, I have two
Walmart desktop LED lights that have that gooseneck feature. I have draped some cloth over the lights and position them at the top far left and right of the microscope so the lighting is even and smooth. Diffusing the light is important and I am sure your creative enough to come up with a way to reduce glare, there are many cheap alternatives out there.
I will probably shoot the "far away" pics on the Trinocular microscope, and then shoot the closeup pics on the binocular microscope. The picture sizes and clarity seems to be spot on for each of those, and I wont ever have to mess with the lighting, unless I get a stubborn coin that is a brown or prooflike that may require a little TLC.
I'll be looking forward to seeing the results of your setup. The modern day cameras are simply amazing and well worth the investment if you like taking pictures of coins for fun and/or eventual sales.