For certified Google/Android TV devices, not yet. It should happen this year since newer shipping chipsets are supporting WiFi 6. As for gigabit ethernet, a number of devices support this.
I haven't looked into USB dongles, like those for a computer, much so that might be an option. Also to note, WiFi 6 doesn't support older devices as well or act weird (I had to turn our AX/6 off on our home router, as multiple devices failed to see the wireless AP).
Boxes like the ones you mention (that isn't an official Android TV), there seems to be a few that support WiFi 6. I wouldn't suggest those as they don't use the TV interfaces like those in certified Google/Android TV nor do they support for Chromecasting DRM-ed content (Netflix, Prime Video, etc).
It seems strange you’d require both, but the shield is the device I’d recommend the most, just wired
Just and gone and bought the mecool km6 deluxe looks like a good spec device.
The Shield has both, i think.
The Mecool KM6 Deluxe edition has Gigabit ethernet and WiFi 6, it's also Google certified but not Netflix Certified, more info at the Mecool Online website, where you can purchase the device with a 15% off if you use the code "mecoolbox" at checkout.