I assume you mean hardware to run as a firewall/router with pfSense rather than just to generate traffic?
The graphics card makes no difference at all here other than potentially being unsupported by pfSense at all making install difficult. Better to use on-board video in most cases or serial console.
You don't mention RAM there but it's not really significant for high throughput.
Network card choice is though. Use something Intel based, ix or ixl.
There is a huge variation in performance across the range of E3 v3 CPUs, you need to be more specific. But the Ryzen 3900X appears more powerful than any of them. In a synthetic benchmark at least.
The 5Gbps VPN requirement is a far harder ask then 10Gbps total throughput. But again there are many variables there.
Steve