Think long, both allow you to try various tube types, which definitely sound different, Ayon is a beauty to look at, never heard one.
I see that you can bridge the Prima Luna into Mono, so the option to double your tube power is there, much easier to try using EL34’s lower output each side, which you don't need now, but future speaker change? That option make make it easier to sell in the future.
Once you pick which unit, then ask again about members various tube experiences. I never had KT120's or 150's, I got hooked on tube sound with EL37's, then EL34's for years, now I am happily using KT88's with a Cayin A-88T which came with 6550's.
Running cool for long life makes a lot of sense.