Desktop graphics cards matter much more than the CPU when it comes to both building and buying a gaming PC. There's a lot to consider when picking out computer graphics cards, from the PC case size to the type of monitor on the system to the gameplay settings you're looking to use. Gaming graphics cards are important for any PC gaming, VR gaming, or Cloud gaming. All in all, the most important thing is to make sure you can use it before you buy it.
Most top-notch gaming graphics cards use a lot more than the 75-watt maximum standard provided by PCIe slots. Such cards will need you to connect supplemental power connectors that usually come in 8-pin and 6-pin varieties. If you have a power supply that does not have the supplemental power connectors you require, then you might need to get an adapter that sources power from a few Molex or SATA connectors. The next logical step is to upgrade.
If you intend to use PC VR platforms, video graphics cards are an important element. then you'll need to use, at the very least, mid-range workstation graphics cards that have optimal performance levels. In fact, you just might want to concentrate on the high-end models of video cards, like the NVIDIA devices. These are well-known to support virtual reality gaming. There are some lower cost options you can use. The Radeon RX family of cards from AMD offer substantial power and response for virtual reality performance. However, most seasoned gamers will advise you to go for the top-tier desktop graphics cards if you're looking for seamless virtual reality gaming.