Turris Omnia is good but for the WiFi6 you need the latest version that is expensive. I got the 2nd version, WiFi 5 I guess, for 40$ second hand. Totally worth it.
The Turris Omnia doesn't seem to have a very performant CPU (low clocked and dual cores). That said, I'm no expert on router performance so might work fine. What's your experience with the 2nd version with WiFi 5?