I ordered mine directly from Kamaka for my Kamaka pineapple, since it didn't fit into any of the cases on hand at the time when I bought it. Some soprano pineapples fit into the Stagg Tweed Case (Amazon and eBay) - just make sure it's the pineapple-shaped one and not the figure-8 shaped one. I know Martins and Favillas fit this case well.
If you search the forums for 'pineapple case' you'll find threads about this. How do I know this? Because I just completed the exercise of buying a pineapple and a case to go with it. The Stagg tweed fits my Mainland Mango Pineapple like a glove.
That Stagg pineapple case fits my Kala Pineapple snug, and my new Ohana Pk-25 less snug, but just as well. I've also seen a pic of a Koaloha Pineapple in that same case on the German Forums. People always comment on the case...