9.25" Celestron Edge HD ota,
AM5 Mount with counterweight or equivalent (The AM5 is small and light which is always handy) Must be equatorial to teach celestial dynamics,
Top shelf ultra wide (80-100 degree) 15mm give or take a couple of mm eyepiece which gives around 150x power. This is perfect for most popular fuzzies,
A bunch of good quality Plossls in the shorter fl's for planetary/lunar/double star use.
Imaging:
Whatever takes your fancy:
One shot colour with a l-enhance filter will give great results and teach about different wavelengths of light too and less fiddly than a filter wheel.
Get a small guide scope using a good colour planetary imager that can be dual purpose guiding or imaging on the main scope.
Science:
A QHY 174M GPS camera for around $2000 will deliver an enormous scientific payload. Asteroidal occultation timing, transiting exoplanets, lunar occultations, asteroid astrometry and the like with genuinely useful data to share with the professional community. Use it in the Lab with a DSLR lens to time experiments to the millisecond. BTW, it is a pretty useful monochrome camera in it's own right too.
Luxury:
V4 Hyperstar for ultra wide imaging or the .7 focal reducer.
And plenty of accessories!
Avoid anything that automates - the students will learn more learn by repetitive manual tasks. If there is any budget left over, but a couple of cheap equatorial refractors of the entirely manual type. Fighting with those things is an awesome way of understanding the sky and equipment. I used to teach observational Astronomy at university and getting a scope set up and pointing at an object was a real challenge for some students and the equipment took a real flogging
