Volunteers rock! Kudos for working with these kids. Survival skills build self-confidence and self-esteem, and maybe a chance to learn trust and teamwork. Seems to me you could change the way they view and interact with the world -- and change their lives for the better. (Enough from the soapbox.)

Scrounging survival gear is a favourite topic of mine. Some ideas:

Knives:
You don't need fancy knives to teach basic knife skills. Personally, I think a short, fixed blade is preferable for first-time users.

I made my young nephew a first and second knife from discarded/broken kitchen butcher knives that I get for free. The local secondhand store knows I can recycle them. As long as the blade is sturdily attached to the handle, just cut down the blade to about 3" which makes them much less susceptible to breaking.

The first one I made was rounded and blunt, except for a recessed notch (1-1/2" long) with a sharp cutting edge. Nearly impossible to hurt yourself by accident, yet you could do a surprising amount of wood carving with it. The second was made with a full-tang 420-J2 1.5mm Japanese steel butcher knife. The cutting edge is about 2-3/4 inches long and is straight, so it's easy to learn sharpening skills. The end is very slightly angled down to the sharp tip. I wrapped some red electrical tape around it so it's hard to lose in the grass. Very sturdy and takes a good edge - I still use it to make kindling at my fire pit.

BTW: you can use a low-powered angle grinder for cutting and shaping these, if you're careful. Fast, light strokes will not harm the temper, in my experience. Finish with a file.

If you talk to secondhand/thrift shop managers, explaining what you're doing, they may collect a bunch of blades for you and give them to you for a song.

Also, there are lots of sources for free steel that will hold an edge. Chop an old lawn mower blade in half, and you have a crude but effective tool. Farmers discard high-carbon blades from the sickles of swathers, combines, haybines by the bushel. Hockey arenas have loads of broken wood-composite sticks that make perfect handles.

I think kids will learn more by improvising with different items. This is a place where unconventional, creative thinking can be rewarded with success and praise.

Wire saw:
The multi-strand variety works surprisingly well. You could cut one in half for kids' use. Add wood toggles for comfort, and tape the sharp ends. I carry one of these on airlines and they don't mind. Perfect for your "no weapons" kids.

Pot:
I wouldn't bother buying pots. A coffee can works brilliantly as a billy pot. Tamp down any sharp spots on the rim, punch a couple of holes for a wire handle, and let them do the rest. The hot chocolate will taste better if you boil and discard the water the first time.

You can also use empty aluminum cans from soda/pop/beer. I've found these (along with empty Bic lighters) in abandoned camps, or floating in rivers, in all sorts of places, so they're a real-world survival asset. Cut open the top partway, so you can lift it with a stick, and boil the heck out of it before you use it. Perfect for practice and demonstrations. Make sure they don't have a coating inside (Guiness cans don't work; there's a coating and a plastic fishing-float widget inside).

Matches:
I don't mind paper matches in kits (airlines again) as long as you have a backup method. If you use them right, they're quite effective. Don't tear them off; cut down along the match right to the bottom of the matchcase, and tear off about four at a time. Now you have a hot match with a long handle. (I also notice that paper matches survive getting damp and drying out much better than wood matches. Had some in an open can in an open shed, and 10 years later they still light. Wood matches in the same can are useless.)

Hope some of this is useful. Keep up the good work.