You can find 10gb compatible switches pretty cheap these days(ruckus, unifi, used cisco). There is no need for anything over cat6. If you pick up a switch with

You can find 10gb compatible switches pretty cheap these days(ruckus, unifi, used cisco). There is no need for anything over cat6. If you pick up a switch with SFP+ ports you can run fiber to the server NIC. Otherwise cat6 will still be plenty. If you have a fiber WAN that's at 1gbs that will be your bottleneck for incoming and outgoing traffic. You will never pull that full gig on domestic fiber. If you are running additional to LAN ports to your switch from your router you still only have one point of failure on your router and switch so the redundancy doesn't gain you anything. Without a second wan connection there is no need for load balancing your outbound/inbound. If your ports on the switch don't need POE turn it off. If you forget to turn it off you wont notice any impact as most modern switches autodetect.