For instance, should I stick with the Big Players like Anderson or can I buy windows from a local manufacturer?
I think most windows have opening mechanisms made by Truth Hardware. Truth Hardware is an industry leader and I doubt there is to too much pressure for new competition in such a poor building market. Truth has a motorized opener system called the Sentry that they licensed from Win-Trol , the developer. Window companies that use Truth mechanisms can offer the motorized systems, but it appears to be such a hodge-podge of licensing agreements, it is hard to say what is up. Ultimately, if your chosen window has Truth Hardware, you can get an opener for it, but the price you will pay ranges from substantial to astronomical and products (generally, motor housings) may differ in cosmetic appearance.
Look up Truth Hardware and WIn-Trol, Inc. and see if you can piece something together from what they offer.