I'd go over to wakegarage, it's a site for the do it your selfer type guy. There are a lot of guys who have made slapper kits, and a few who have done the trim tab route. There are also a bunch of home grown wake plates, one guy has one with the exhaust in it. Even if you don't see exactly what you are thinking it's a good place to spitball your ideas and get feedback. It isn't brand specific and there is no My boat is bigger than your boat stuff. Mostly guys with slightly older boats doing home brew projects to try to get something comparable to the newer boats. also good info on boat maintenance etc. for the do it your self guy.
I don't own the site, I don't get a commission, the site is free and I am not trying to down talk this site, I love it here, but for the projects I think that's the place.