That picture is of a catamaran trapeze assembly, it won't work well on a dinghy. Don't buy it. There's no use for the linked blocks, the lower piece of rope and the stopper, and even the "Can't miss" type rings are a little pointless. Also, the "t"-shaped handles (which are ok as such) make wire length very critical. A rope + "doughnut" type of handle would be easier to install. Sounds like overkill. The bags are for holding the spinnaker (and lunch) in place, not for lifting the boat. There won't be any big loads on the fastenings. If the laminate is very thin, bolts with oversized washers will be good enough. (What hooks?) Just ask Wavedancer to do it.