is there a way to buy just gpu components to build a gpu card?
if so i have a homemade gpu liquid cooling block idea
Yes. AMD will give you a copy of their reference design which includes the schematics, parts list, probably gerber files for the board layout, and maybe even reference drivers.
I don't know who the distributor for AMD is, but Avnet would be a good place to start to buy the GPUs. Unfortunately, they are probably on allocation given the worldwide demand for graphics cards.
You'll have to hire someone to assemble the boards since fine pitch BGAs are outside the capability of most hobbyists (and Microsoft too <rimshot>)