I'm jumping into this way late I know, but just for the sake of knowledge, you can buy extended barrels from a company called Fire Dragon
http://www.efkfiredragon.com/ They don't list CZ's but they have made barrels for them in the past. I have bought both threaded abd ported barrels from them. you may well have to fit the barrels to the pistol but they are a source.
Also late last year (now that sounds weird, late last year
) CZCustom and CZ-USA announced that they also are selling extended barrels for CZ's in both thread and non threaded barrels. However, although you can buy them it is highly
Recommended by both that you have them fit the barrel to your pistol(s) at an extra cost.
I'm not saying anything about anything other than that I know of those two places. If you are goo to go with doing the Mods that Atlas suggests then have at it, this is more or less intended for those that aren't u to or don't have the equipment to turn down a barrel or open the crown on the slide