Holsters totally depend on the application. A blanket statement of "Kydex is unreliable" is ignorant - anything badly made is unreliable, and Kydex holsters can be badly made, just like leather ones can be.
Big, fat, bulky duty holsters like many Safariland series are also made from materials like Kydex - all you need is something that's close in terms of fit, and a heat gun, and you're done. I'd start with a CZ-75/TZ-75 or Sig 220 holster in that case, and mold up/mold down from there.
For personal carry, there are lots of people making holsters on the side, both leather and Kydex. Many will work with you to get you something that'll work for you. If they're Kydex or part-Kydex the heat gun method works as well.
Lastly, online forums dedicated to the CZ will probably have a compatibility list for each gun. For CZ guns, the double-stack SIG holsters are going to be pretty close in terms of fit.