DELL Precision T3500 Workstation

Intel HEXA Core Xeon X5650 2.66GHz, 16GB DDR3, 250 SSD, nVidia Quadro 4000, Motherboard LGA1366 DDR3

I had Mojave with Clover on this.

1. What upgrade to make to to be able to run Big sur?
2. If I get a AMD RX560 GPU will big sur be possible?