Wish my friend, Ron Frisosky, who taught me about trailers was alive but was one who designed them. Suggest if looking, look at Majic Tilt and Road King. You will want a tandem axle with surge brakes if considering launching. If buying the trailer for a specific boat you may want to get bunk boards, otherwise the adjustable pads, three each side minimum. The trailer will need of course a keel tray but make sure the edges are not that high. Never transport a keel on a bare metal keel tray as the boat will slide but suggest treated lumber in the bottom of the keel tray. I never was a fan of power boat do overs into sailboats unless you know what you are doing. The cost of a new trailer is not cheap. In addition you will need to have an extension and for a trip be advised to carry a spare or two, four way lug wrench, grease gun, floor jack, blocks of wood with several with 45 degree cuts to block or chock wheels. There are few other items but you get the gist. Always go 10-20 miles and pull over to check straps and wheel hubs(ok if luke warm but if hot, stop as you have a problem) I would suggest looking at Road King and if you have any questions, call Larry or Phyllis with RoadKing in Asheville, NC as they know trailers. Ron worked for them and we were friends.