Sorry Stuman I've kinda turned your thread into "trailer talk".
But still this is really interesting with the difference everyone has launching their boats. I hope you find a winch system that works.
For now I'm going with a $23 strap from bunnings that's rated up to 3.2 tonne. It "should" be long enough.
I'm still puzzled how my witch has gained over 500lb over everyone else's

although she has got an old space sailor trailer and she has got added glass on the inside. Guessing I have one of the first versions too with the one storage compartment on one side and the v berth that wraps all the way round on the other side. Might have weighed a little more, who knows.