I know SUSE Enterprise Linux is popular in the EU, but I’ve quite frankly had enough of corporate sponsored distributions. A few bad quarters and things could get interesting for the community oriented distributions.
I’ve moved back to Debian (with Flatpak) and will use the testing kernel for hardware reasons as soon as I remember where I put my notes on it or get tired and look it up.
I was researching this option last year and after talking with the Asahi crew via IRC, their advice was at least 16GB of memory and 512GB for SSD because you do have to keep macOS around for certain tasks, like firmware updates. With smaller amounts of disk space and memory, the system will use swap which can use a lot of the write cycles on the SSD.
You should probably check to see if this is still their recommendation.
Just because source is available does not mean it’s an open source license. It’s still proprietary, free to use for non-commercial use only.