Dario,
It's been years since I installed the Gaia II, so I don't recall if I used adapters or not. I also don't know the pitch. Why don't you address your questions to Lou Hinkley? He's very helpful.
Thank you Mresseguie for your reply.
I will ask Lou directly for some suggestions, because the idea of taking the Ulysses down from the stands without certainty of installing the Gaia, with the risks of moving the speakers, discourages me from doing it without assurance of a successful replacement with the Gaia. Moreover, there is still the situation of further lowering the speakers, which goes against the logic of raising the tweeters a bit to better align them with ear level...
Best regards, Dario