Buying New Microscopes for 9th Graders

Hello, I am in the process of purchasing a classroom set (15) microscopes for 9th grade science. However, I can't find reviews of brands anywhere. I'm just looking for some general advice about the usability/reliability of various popular brands.

I am looking at:
-monocular eyepiece
-up to 40X
-stationary stage
-movable condenser
-iris
-cordless/rechargeable LED

Brands considering:
-Boreal 2
-Boreal
-Wolfe Microscopes
-Skope
-Leica

It looks like what I'm looking for ranges from about $250-300. Any help would be greatly appreciated.

Thank you,
Mark