I just picked up a second boat slip and it will be used to dock jet skis. I found used hydroport 2 for sale. I know very little about the plastic docks.
There a several folks in my nieghborhood who use those for thier jet boats and PWC. They seem to hold up allright. Biggest gripe I hear is that they don't take antifouling paint well, so after a while getting them clean is a problem ( I am in the Northeast, and the docks come out for the winter due to ice. The fouling makes them heavier, so you ignore it at your peril)