IMHO what is important for VR is the overall system performance like:
- for PSU - stable voltage supply, more rails are always better, x 2 - 2.5 wattage more than overall system requirements (CPU +GF +HDDs+ cooling + anything extra);
- for mainboard - number of PCI-E lines and their performance (for graphic card OC), processor OC capabilities (how fast the cores can run), memory OC capabilities, stable power, so the higher chipset level plus good extra OC options (by the manufacturer) are the must;
- for CPU - single core performance plus large cache size are most important , OC to 4.7 - 4.9 GHz should be doable depending on cooling options, INTEL i7 or RYZEN 7 or even 5 series have more than enough cores for comfortable gaming;
- for memory - 16 Gb DDR dual channel is enough, quad channel (like LGA2011) is not proven to improve VR performance, memory clocks and OC capabilities are most important (higher memory clocks like 3200 - 3600 is a must);
- for storage - M.2 (NVMe) disks are better than SSD, SSD are better than hybrid HDDs, so M.2 (NVMe) for system data plus SSD or hybrid for other data depending on your budget, or only M.2 for everything if you have money to burn, though you have to be careful with second etc M.2 because of it can slow down PCI-E bus depending on the mainboard;
- for graphics - 1080Ti (11Gb) or 2080 (8GB) or 2080Ti (11Gb) based on your choice, 4K or 5K+ VR gaming can get close to 6-8Gb memory utilisation, 1080Ti in 4K gaming is on par with 2080 and 10 - 15 % slower than 2080Ti, but 2080 and 2080Ti maybe will have some advantage over 1080Ti in future due to the new features (not implemented in games or used by Pimax yet, but potentially can lower the overall graphics card load in fixed FOV scenarios, ray tracing etc);
- cooling - water cooling is better, but more expensive, for me closed systems looks better, like Corsair i80 for CPU plus EK 140mm radiator + graphic card waterblock, or EK MLC AIO with 360mm radiator with CPU and graphic card waterblocks;