Suva and Gaia adapters the same

If by “adapters” you mean thread size for your speakers, Stack will supply the proper size threads for your particular speaker or stand. I needed 3/8” US, which they were able to supply.  The adapters are removable in case you need a different thread for another application.  

If you are trying to learn what the thread size is for the footer itself, meaning the female threads, the Auva is M8. I don't have the info about the Gaia.

The "adapters'  are pretty universal.  The threads that came in the Gaia box didn't fit my speakers.  I contacted Iso Acoustic and they sent the proper ones no charge.  Good cust. service.

There is no reason you can't use one from the other brand.  

You can also find threaded adapters with different threads each end at McMaster Carr.