I used to use Primos until one day an old turkey hunter from Alabama that knows Butski told me I ought to try one of Paul's diaphragms. Being a true "southerner", I declared there was no way a Georgia boy was gonna buy a turkey call made by a "yankee". So he handed me one, told me it was free, and said, "just try it". I did and had to eat my words. I've never used anything else since. No reason to.

I have found them in a shop or two in Alabama. But mainly in catalogs like http://www.wingsupply.com and another catalog that I cannot remember at the moment.
You can also buy directly from Butski. I know he has been fading back a bit, but I don't think he's going to drop out of business. I'll make a contact and try to find out if he's gonna stay in business.

His Spring Shadow, Cuttin Caller IV, and Phantom V Cutt are the only diaphragms that I use.

No jakes!