Most certainly contact other schools like universities to see if they would be willing to donate microscopes. They often do, especially for education.

Keep an eye on the overstock and "open box" scopes available. https://amscope.com/collections/open-box-compound-microscopes

You can add a camera easy enough to any scope. Any standard sized microscope camera works in any standard sized microscope once you remove the eyepiece first. So don't let having a camera bundled in affect your purchasing decision unless you're getting a deal for the camera in the bundle.

And of course, a super cheap way to show kids the joy of microscopy would be some of those cheapie "USB digital microscopes" you can get for 15-40 bucks. I know, they are toys, totally. But super fun ones with some surprisingly good magnification. I've been really impressed with the two I got. Realistic magnification is about 300x max. You'll see non-transparent stuff that's 0.5mm and up just fine. Get a decent stand and it's basically a digital stereoscope with 40x-300x magnification. Pretty decent wifi one with a decent stand here for a little more than normal ones. https://www.svbony.com/SM401-Wireless-Microscope/

Other ones for more money have attached screens that would be ideal for a classroom for kids to walk up and use. Better than a pocket microscope by far, and you can easily share them on a screen. They are super low resolution but just so easy to pass around and let kids play with 'em. Still can see a lot of pond life. And everyone digs checking out their face and arms with 'em. Using the wifi version with a cheap android tablet is just ideal for generating classroom interest as you graduate them into the world of 400x biological viewing with a compound scope. Note: You need a wifi one to work with iPad/iPhone. Both wifi and wired ones work great with android/windows/mac/linux.

For showing kids introductory level stuff and let 'em look at cool things... absolutely get a pack of prepared slides. https://www.amazon.com/gp/product/B07GRN4H38/

I got those for my grandson. They are plastic, cheap, low-quality, and safe. Kids don't care. They just wanna see gross stuff close up :D

Don't we all?

But for 400x and up viewing when you'll be working with dyes and preparing slides and all that fun stuff (learning curve)... you're on the right track with those scopes. Both excellent choices. I have the monocular version of that Amscope one and I love it. Remember with a 100x objective and 10x eyepiece at 1000x magnification, you also need to use oil immersion as the air itself blurs the image. Again, learning curve there as using immersion oil incorrectly, on the wrong objective or just not cleaning it afterwards, ruins the objective. Honestly for student classroom stuff, you'll be fine at 400x unless you want to look at chromosomes and tiny bacteria. 400x is perfectly fine to do cheek swabs and look at cheek cells, or blood, really - most cells.

But you do have to prepare the slides and all that fun stuff for biological viewing at 400x. Things get awfully transparent that small and need to be dyed with the correct, and often toxic, dyes.

Don't get tricked into scopes claiming super high magnification. The rule of thumb is 1000x is the most you need. Stay away from barlows and extender lenses on scopes because there is no need for them beyond marketing by claiming stupid high magnification. They just degrade image quality. Similarly, high magnification eyepieces are also magnifying at the cost of image quality. Your quality comes from the light and objectives, not 25x eyepieces with tiny fields of view.

As with telescopes, microscopes are marketed by claiming false magnification levels that sound super duper high. But with both, light is the limiting factor. And much past 1000x magnification you're getting close to the wavelength of light (~700-400nm). Anything much smaller than a micrometer isn't going to be interacting with light much anymore. And electron microscopes are kinda pricey...

Guess what I'm saying is for 4th and 5th graders, you might be looking at more expensive microscopes than you need to be doing. A less expensive student scope is fine for that level. Kids that age aren't gonna make a lot of use of 400x and up viewing. A student scope with 3 objectives at 4x, 10x and 40x and just a normal 10x eyepiece is plenty and much cheaper. The two you mentioned are more for 7th graders and up.

Example of a less expensive but still decent quality student scope for grade-schoolers, with 3d mechanical stage: https://www.svbony.com/sv601-portable-microscope/

You'll note it has non-standard objectives (not RMS threaded). But they are still decent quality - much nicer than the toy scopes you get for little kids. These range of scopes will also have mirrors instead of a prism. They won't have a light condenser worth a darn, no iris diaphragm to match the objective's aperture. Just a dimmer. They aren't great. But they're cheap and ideal for that age group. One of those with a cheapie 0.3 or 1.3 MP camera is gonna be just fine for those kids to get them started out with microscopes, and they see many cells just fine. Can even see blood cells at 5um. Barely. Not great, it's a cheaper scope, but absolutely fine for kids that age.

For yourself and for one-on-one guiding a kid as they use it - those are both excellent microscopes you're looking at. But donating scopes to a school... I'd stick with cheaper digital and student grade scopes that are easier to replace.