Is there a board/part I can buy anywhere for a turbo duo component or s-video mod?
Go here to get your component board. http://tg16pcemods.bigcartel.com/ (http://tg16pcemods.bigcartel.com/)
S-video on the other hand would require you to install the few parts yourself. No board option.
Here is an s-video diagram I made a while back. (https://s18.postimg.cc/cupxd5l3d/S_video_Mod.gif)