@shivakrishna
Just a quick note:
This build guide should work with most Gigabyte Z390 boards, but the USB and Thunderbolt SSDTs are only for the Designare Z390. This guide will be most effective if you use the Designare Z390 motherboard. All other components (memory, GPU, CPU cooler, power supply, NVMe SSD, etc.) are fairly interchangeable.
UPDATE: In general, we should choose a card that is as close to the AMD Reference design as possible. The PowerColor Radeon RX 580 Red Dragon is a good choice. if you look at my signature below, you'll see that I'm using Powercolor RX 580 and Powercolor RX 5700 XT.