Yes, you can build a Hackintosh.
Yes, you can build a Hackintosh.
Consider installing the operating system first and then upgrade the GPU later if needed.
As noted here, getting the operating system without owning a Mac yourself constitutes piracy. Apple only provides the OS after you own their hardware; any alternative methods for obtaining it are considered illegal.
I'm aware of this and as mentioned I planned to own an Official MAC OS. However, theres literally an "Ultimate Hackintosh Build Guide" on the platform.