The swim platform is the same as the one that is connected to the hydraulics. First, contact Latham Marine. They are the manufacturer of the hydraulic components (also the non-hydraulic components you currently have). This, of course, is assuming you want the factory platform. There are aftermarket platforms that might be less expensive. By the time you are done with purchase, fiberglass modifications and installation you are looking at $15K - $25K of expense (depending on whether on not you are capable of performing the work yourself).
This post probably should be moved to Performance Cruisers.