You are off to a good start there, keep the schedule up!
We did a make your own gear project a few years ago that was a good experience for the boys and the leaders learned a few things too. We also saved a ton of money building our own gear rather than writing a check, but to me the most valuable lesson was that we could indeed make our own gear and even if it's not a perfect stitch it holds up and that sense of "I made this myself" is a pretty cool thing to pass along to our youth.
A few yards per hammock at Hancock Fabrics or your store of choice along with a large spool of high quality polyester thread will get you headed in the right direction. That and a pattern, either from Papa Smurf (which might be at camp at the moment) or one of the many other members here.