CZ75Bs in .40 S&W came with ambidextrous thumb safeties, as did the CZ75SA pistols in 9MM or .40 S&W.
If you absolutely can't put up with the firing pin block there are other CZ pistol options.
Then remove the firing pin block/spring, the lifter arm and spring and put a spacer in the sear cage where the lifter arm/spring were. Get a nice hammer from CZ Custom or Cajun Gun Works and an adjustable sear from Cajun Gun Works
If you don't like the .40, put a 9MM slide/barrel on it (you'll have to remove the firing pin block/spring in the 9MM slide).
Pay no attention to the right side slide release and Pre B style hammer. I added those because I like CZ85's (Pre B's with the spur hammer, I mean.) The ambidextrous thumb safeties are like what you'd find on a Pre B CZ85.

If you could find a Pre B CZ85 you'd have a CZ75 with not firing pin block and safeties on both sides of the pistol frame.
The Pre B CZ85 I bought and had refinished (before I had it refinished). No firing pin block in these either.

