> need to buy some AOS4 and/or MOS capable hardware (not EOL ones) [...]
> so this was just an idea.

As I understand, the ARIA board is EOL and what‘s available are remnants. Or is the ARIA still being produced (per order)?

> Better would be to have some PowerArch T or P series NXP cpu.

MorphOS 3.10 is supposed to support the P5-based A-Eon Cyrus Plus board (AmigaOne X5000).