As with light microscopes there are new, questionable quality, cheap options and old, similarly priced options which are more reliable and often better. I'd recommend getting an old used scope from one of the "known brands"; they're easier to get serviced and parts more readily found online if something breaks.

I like my Bausch and Lomb StereoZoom 7, but I've seen recommendations for Nikon SMZ-2T and Olympus SZH10.

Those scopes have options for photo ports, but they're kinda hard to find and expensive. If you're going to be taking measurements often that might be something to consider, a digital camera hooked up to a computer is a nice workflow for this. Otherwise an ocular with reticles works great, it's just a bit slower.