On my Mac25 I used a couple of these swivel/cam cleat/fairleads mounted on track cars. I used a 2' track. They worked really well. I bought these when I misplaced my other ones but never got around to mounting them on tracks. They can be used with out tracks but I had 100, 135 and 150 jib and needed the track.
I really liked them because I could set the sheets from the windward side of the boat. They can also be used with a winch since they swivel. I seldom needed the winch except when the wind picked up and I was still on the Genoa. Here is a picture of the ones I had on the Mac 25.
I will be selling them on EBay soon. If you are interested in them send me a pm.