Chosen Solution
My first Mac was in 1984. I still love all my Mac’s. I am writing this because I need a shopping list for the necessary third party, or off the shelf, Mac compatible socketed hardware to complete a (non-architecture of the Windows operating system) pen-enabled tablet computer that is somewhat along the lines of the Modbook Pro that was targeted for creative professionals in need of more than enough horsepower to run macOS and my substantial amount of of creative software.
Sorry guy, You won’t find a laptop class system with a socketed CPU that would offer the performance you are looking for. The industry as a whole have moved to factory mounted CPU & GPU chips. The nearest you can get is a luggable gamers box. Basically, this is a desktop class logic board held is a small form factor case. If you really want to go crazy see if you can pull together a gofundme project taking a 17” MacBook Pro (because it has the space) to get a custom build a logic board made. Thats what I would do.