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.