If you want a real keyboard, get the
Matias Quiet Pro or
Tactile Pro with real keys and mechanical switches they are so good that they don't need backlights, but they cost $125-150 and I doubt that his school would order 30 of them.
OP: If you're going non-Apple and your educational goal is not to deter your students from doing productive work on a computer, try to find something that has real keys with sculpted keytops. It's more comfortable to type on and more ergonomic.
The
Matias USB 2.0 Keyboard for Mac and PC with Mouse for $36.50 would be perfect, it has both the keys for Mac and Windows in case you're running Bootcamp as well. Otherwise, there's also a
version for Mac only with for $41 or
just the Mac-only keyboard for $30. Just for the record, they don't have mechanical switches like the keyboard above, but they'll still be a pleasure to type on.