Check out USA ARCHERY, of course mentioned NASP, 4H, After School Archery Program, NADA, national archery developmen association?? State wildlife dnr type programs, Lots out there these days. Some of these overlap and many have similarities in the steps to archery. Our club has many certified instructors through USAArchery programs, we do an intro to archery program and we have JOAD a program. Three Rivers Parks District in the Twin Cities of MN has a very active archery program. I've got a contact there but I'm headed off to work, PM and I'll see what I can do if your interested in contacts.
For Equipment you can buy set ups all ready to go through NASP, After School Archery Programs, some bowyers and manufactures have good stock.
Our club uses gensis bows, old comets recurves, other recurves most bought through ********* archery, some really light wieght laminated bows made by club members, about half our bows are gensis about half recurves we probably have at least 40 bows give or take...
A viable program for your park system is definately doable!