Hi everyone!

I just ordered an Aurora R12 that is being built. It will come with a 1TB 7200RPM SATA 6Gb/s. I plan on getting rid of this and switching to using a M.2 PCIe NVMe SSD as the boot drive. 

I am thinking of getting this: 980 PRO PCIe 4.0 NVMe SSD 1TB (https://www.samsung.com/us/computing/memory-storage/solid-state-drives/980-pro-pcie-4-0-nvme-ssd-1tb-mz-v8p1t0b-am/) . I noticed that the R12 only has PCIe 3.0. 

1) Is there any benefit in getting a PCIe 4.0 when the motherboard only supports PCIe 3.0? Should I instead get an SSD that is PCIe 3.0?

2) Do you recommend I reinstall the OS and let the NVMe SSD be the boot partition for faster OS as well as game startup time? 

Thanks!