April gives you plenty of time to prepare.
Get material for tarps and make your own. Usually 10x10 is a good size for two or three scouts. Of course, all the guys will need some instruction on sewing. But straight stitching is easy. Small needles, fine poly thread, with reinforcing patches and loops for staking it down/proping it up. Alternativly, you could use a blue tarp, but these are quite heavy. Lay out space might be difficult, but accuracy is not real essential. Most of what you need in knowledge can be picked up and printed from on-line resouces.
A 0F synthetic bag is usually found for less than $50. DO NOT overly compress these. So, a larger pack for the scouts is likely needed.
Food: For one night, this is not too important. At least 1 larger 3L pot per three or four scouts. 1 cup for each scout, and, a small 3 cup K-mart grease pot works well as personal cook kits. Aluminum is just as light as Ti (or lighter) and far less expensive. Try Bassmasters, they had some cheap "tin" cups. Teen agers eat a LOT of food, as I am thinking of it. Figure enough! (Snacks, water, too)
Pads are a little more important. A CCF pad, at least a 1/2" variety, should work for spring. Cut and fold them with Duct Tape so they fit in the pack. For spring conditions, a second pad would come in handy. For a frameless pack, they can be cut & taped in a rectangle, siffening the pack suspension. A 25 cent table spoon works pretty well, picked up at the local second hand shop.
Ground cloth: this can be some simple plastic sheeting. Cit this about 3" larger than the pad. Tyvec, or PU coated silnylon is better, but more expensive.
Everyone needs a stuff sack. Loaded with extra clothes (after changing into night cloths) it makes a good pillow as well as a good organizer for food. Again, a MYOG project.
A good sized pack from Wally world will probably be the cheapest. Figure ~4500ci. Extra cloths, pads inside, generally overloading with with "goodies", etc all require space.
Rain panchos: A garbage bag works for one trip. Show them how to cut holes for the head and arms. Coming out, show them how to tie it off and use it for trash if it isn't raining. Have them bring two...
Whatever you teach the scouts about weight will probably not be important. You need to set up a demonstration. A 15 pound pack for one night, or a 35 pound pack for one night. Compare functionality, why it works, what NOT to do, also. They will likely still carry ~25 pounds, but will know better, anyway. Some will take away everything you say, so do not scrimp on clothing. Younger scouts may need more than older scouts. Explain why.
Water, washing, toilet: Bring enough, but show them how to conserve wash water (wet bandana, brushing teeth, etc.) Show them what a good kitty hole looks like. Explain why all that is important.
First Aid...well, you need a good kit...'nuff said.