Check out the Openhornet project. It has a 3d scan of a real throttle grip and I think it also has a part list for the switches used or are similar to the switches used in the real thing.
The discord of the project is also great for any questions you have regarding the f18 instruments they can give you a list of the switches used or cheaper solutions that will work fine.
Your grip looks really good for having to work with pictures only.
Also I would recommend to figure out a way to have the entire grip in 1 piece with a cover plate on the inside faces of the 2 grips. The openhornet versions are split down the middle leaving you with "ugly" split lines down the center of each grip.
Perhaps I will redo them in full aluminium in the future with some design tweaks to clean them up.