[willy]

Sounds like a CZ might work for you if you can find one at agood price. For what you want to do though you will need a durable weapon with as many rounds as you shoot. I would stick with the quality arms and find a good used deal. Watch the Dan wessons, owned one in the early eighties with the interchangeable barrels. Could be a pain in the arse to use the feeler guage and set the cylinder gap right and still would spit lead because the timing arm for them was made with a wear prone metal.
If you are considering a revolver for this practice I would recommend you pick up a Smith and Wesson in 9MM. It should be cheap on the used market and they were well made and shot well once you find the right ammo, as any gun is.
As far as the comments earlier about the Sigs take down lever it sounds like they had a bad production run with that piece. It happens to all manufactures. One big difference with Sig is they will fix it right away and pay for any refits needed, they stand behind their product.
There are millions of them in police duty just here in the U.S and there are many like the 226's we had that were sold used after 16 years of use and abuse to another department and I guarantee you they are still shooting the crap out of them.
I was an armorer for the Sigs and they are made well.
If you want to see something really nice take a look at the older German made Sigs like the 225 in 9mm I carried for years and still own. Very sweet with great triggers and high quality steel and maching.