Yeah...get a sail cover. How much?!?!?...who does canvas in your area? Ask them. You could also try Sailrite.com.
Roller furling's going to cost you more than you'll like. Homemade?....uh uh...don't think so. C'mon, we're talking about a 16 foot boat, so how hard is it to raise the jib? Just leave the jib hanked onto the forestay all the time and put a cover on it, too. Whole lot cheaper than roller furling. You can probably find a ready-made bag for it....Sailrite?