Padeyes
If your boat was originally delivered with Genneker hardware, it should have extra padeyes at the bow and one at each corner of the stern. From these you can attach standard swivel blocks. one for the tack line at the bow, and one for each sheet at the stern to turn the sheets forward to the winches. I wouldn't recommend snatch blocks for a couple of reasons. First, good ones are too expensive, second, at the stern you are turning your sheets through too much of an angle. Generally snatch blocks are designed to be wrapped not much more than 135 degrees. More than that puts too much load on the blocks. I will admit that a genneker isn't going to put as much load on the blocks in light air as a bigger jib in heavier air, but loading is still something to consider. As you could imagine, it can be easy to lose a snatch block over the side at a most inopportune moment if a safety line isn't attached, and over time, if you keep attaching to the same point on the to rail, that will begin to become distorted.
