agree the keyboard-in-one is great -

also fyi the pi-top project has a DIY 'all in one' for the PI:

https://www.pi-top.com/products/pi-top-ceed

and a DIY laptop:

https://www.pi-top.com/products/pi-top-3

only claim pi-3 compatibility at the moment, not sure if it would still work with 4, probably need some adapters or so

(maybe other projects like this, not sure)