I think you might be misusing the term "sheet." The sheet is not the sail itself. Rather, it's the line attached to the clew of the sail. On your
boat you have two
jib sheets and a mainsheet.
Your boat is small enough that many would opt not to install
roller furling on the
jib simply because it's so easy to hoist and douse a sail that size. One thing to realize is that if you went to
roller furling, you'd either have to
purchase a new jib or have a
sailmaker replace the hanks that you use to attach the jib to the headstay with a boltrope used to attach the jib to the foil of the furler.
I doubt you'd be happy with any furler
sold used. To begin with, it would have to be the exact size of your headstay. Chances of finding a decent one the proper size still in working condition are negligible.