I'd throw in another vote for Heroic. I tend to use it for pretty much everything that I have that's not on Steam. It'll let you choose what version of wine/proton-GE/proton you need to get your games working.

You can sign into GOG inside the app and have access to your library. Same for Epic Games Store and Prime Gaming, as well as the storefronts (tho the Epic one isn't working for me rn, but the other two do). After signing in, you go into the library view and then it should list all the games it finds in your store libraries, then you can pick the one you want to download and install. It'll ask you where you want to install it, and then under 'Show Wine Settings' you can pick what version of Wine or Proton you want to use