If you feel brave, you can modify your CZ-75 so that the safety will engage with the hammer down.
If you take a good look at your hammer's "half-cock notch" (close to hammer face), you'll notice it has a sort of hump between it's sear engagement face and the hammer face. This hump blocks the safety from engaging by keeping the forward-left protrusion of the sear low and against the safety notch. If you remove your slide and take a look, you'll see what I'm talking about. If you remove that hump, the safety will engage with the hammer down.
If you're super brave, you could increase the face of the half-cock notch, by cutting down toward the hammer pivot, and be able to engage the safety at half-cock.
Of course, you'll have to disassemble your CZ almost completely to get the hammer out, but that's a skill you should eventually develope anyway.