I see the Sovereign measures 22.05 mm Will it fit in a 22mm air-tite or maybe the 22mm air-tite with black ring or do I need to get a 23mm?
I can recommend Lighthouse Quadrum intercept holders. I don't own any Sovereigns but if a coin's diameter exceeds the holder size only slightly then there shouldn't be any issue, as the inserts are made of a soft material (which is free from acids or chemical softeners).
I use 22mm and it fits just fine (22mm refers to the diameter of the black ring, which can stretch slightly; the outer plastic fits fine). The advantage to 22mm is not only does it fit snugly, it's easy to find, as they're also used for 1/4 AGEs, APEs, and nickels.