Looking to move to a Tube Integrated setup

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.

Of the two, despite the beauty of the Ayon, I would go with the Prima Luna's. There are a lot of good points made by Kevin in that video. I've heard my friend's Prima Luna Mono Blocks on his JSE Infinite Slope Model II's which I helped him get/setup (I owned/loved mine for years), and on his current speakers which he prefers, I forget the maker, but they sound terrific, we both prefer tubes to his prior SS. 

Running them cool for long life combined with the adaptive auto-bias dream feature, makes me want one, my early Cayin has manual and dangerous internal bias adjusters. 

Spare tubes should always be on hand, you would only need a few, I gather that they will come with KT120's. As it is a major shift to Tube sound, I would encourage you to buy (now or eventually) a batch of EL34's, and compare them.

Break in new tubes: on, no input needed, just leave them on for around 60 hours is what Brent Jesse advised me to do.