Best OS/setup for raid10 2x6tb and 2x12tb?

Hi all,

I'm building my first nas and currently trying unraid on a test machine only to realize unraid isn't actually raid (I know silly mistake). I've already bought my drives so I'm looking to make it work with what I have. I have 2x6tb reds and 2x14tb red + ironwolf (had a spare of each so I just bought a matching one for each to pair up thinking I could raid 1).

Ideally, my first scenario that I'd love to make happen is:

• raid 10 where 6tb (mirrored) from the 2x6tb and 6tb (mirrored) from the 2x12tb are used in raid 10 config, while the remaining 8tb (mirrored) from the 2x14tb can be raid1.

If that's not possible, then my fallback would just be:

• raid 1 both pairs, i.e. 2x6tb raid 1 so I have 6tb of mirrored storage and 2x14tb raid 1 so I have another 14tb of mirrored storage.

I've grown to like unraid since it would've allowed me to add more later and easily supports SSD cache but it doesn't looking like it will be able to support my desired configuration with the drives I have. Is my first ideal scenario possible? If so, which OS would allow me to do it in the easiest manner? If not, perhaps my fallback. TIA