Schaefer makes chainplates but they are all basic stainless chainplates and not what you are after. Here's the link to their chainplate page.
Schaefer Marine Hardware - Product Catalog
Harken is a very innovative company. But chainplates are not really an innovative type of product. They do not make them. Not in my catalog or their online catalog. They are also boat specific so the market would not be worthwhile. The chainplates that come with the boat will last decades if not the life of the boat. Every boat design has different requirements and other than a straight bar type of chainplate which Schaefer has there probably isn't one available to fit your needs. Every rig has different angles and hole sizes and every deck design is different as far as angle is concerned.
Your best bet is to draw exactly what you want, go to a good metal shop specializing in stainless steel and having them custom made. Use 316 and get them electro-polished for the best corrosion resistance. Anyone I know who has either built or restored a boat and needs chainplates, unless they are simple bar stock, gets them custom made as I have in the past.