Regardless of the moustache, a mask that doesn't really fit can be prone to leak or be uncomfortable, possibly both.The reason I'm so insistent on frameless 2 is because I have moustache and I read the it has one of the softest skirts. While I suspect I'll need some kind of cream to prevent leaks altogether, I'd hope that frameless 2 would provide me with the best baseline.
Buying a mask without trying on is a gamble, so I would take one that has been tested and fits well over one that has softer skirt but unknown fit.
As an aside, the original Atomic Frameless is one of two masks that fit me very well, but the Atomic Framless 2 does not fit. So a good point made by Nemrod above.