I got the Avocet from a random tandem place in Kansas City called Precision Tandems- I think it was the last one they had, but they might be willing to order one. The saddle comes in both a titanium railed and a Cro-mo version. I had originally been hoping to get the titanium one and this particular shop had one in their inventory (it turned out that while it was listed in their inventory, they'd actually sold out of the titanium one and when they checked with Avocet for me it was unavailable). Anyway, they pointed out that the cro-mo version is only 20 grams heavier and I went with that (and again it's still lighter than any saddle I've ever had). I'd google Avocet O2 Air 40 women's and I think you'll find a few options. (Or ask your LBS if they can order it.)

I haven't asked how returns work. I'm generally learning that 30 days isn't near enough for me (it took me a year to give up on the Brooks). Fortunately neither the Avocet or the Beetle were super-expensive.