servethehome.com has a series about these fanless, multi-gigabit firewall for a while, might be interesting if you have a 200-300 USD budget?
https://www.servethehome.com/tag/firewall/
I’ve used a very similar setup in the past (J1900 CPU, 4x1 Gbps network ports) and I only replaced it due to reasons. Not noticed any performance bottle necks with that setup.
The latest N100/N200/N300/N305 CPUs from Intel looks really interesting, similar performance as my workstation but at a 10th of the power usage. N305 also has 8 cores in a passively cooled case, amazing stuff!
Kitty on Linux and macOS. Works fine, but you have to install the terminal profile on some systems which is tedious (but easy).
Also, everyone should be using mosh/mobile shell as it’s awesome.