I may be able to help clarify a bit here, but if I'm mistaken, maybe somebody else can jump in...
The difference between the top two pics appears to be the magazine base pad, which is the part at the bottom of the magazine that looks bigger in one pic than the other. All the CZ 75 mags I own (and I own 7 of them, from two different brands) have the thinner base pad (like the top pic). The second pic might be an after market base pad, or there may be some magazines that come like that from the factory, but I'm not sure of that? On the CZ website, it looks like the SP-01 models come with the thicker base pad, but I own a non-SP-01 so all mine have the thin base.
Regarding the two bottom pics, the second last pic is a CZ 75 Shadowline, while the bottom one appears to be a CZ 75 SP-01 Shadowline. The SP-01 part means the full length dust cover with accessory rail (dust cover is the part of the frame that extends forward under the front part of the slide. A "regular" CZ 75 has the shorter dust cover with no rail).
There is a bit of confusion because a popular version of the CZ 75 SP-01 is called the "Shadow", and it lacks a firing pin block (something some folks feel makes the trigger pull smoother or lighter? I'm not sure on that part). There is a CZ 75 SP-01 that is not a "Shadow", but it doesn't seem to be as common in Canada (again, I'm not sure about the relative popularity of the two versions of SP-01 in Canada, just going based on the fact that many ads for sale seem to be for the "Shadow" model SP-01).
A regular CZ 75 (not SP-01) has the firing pin block, and goes by model CZ 75 B (B for firing pin "block", I presume?)
The Shadowline CZ75 has no firing pin block and a short, unrailed dust cover (that's the model I own) to make it different from a CZ 75 B. It also has a few other differences, like a different shape hammer, aluminum grips, low profile "thin" safeties, nickel plated trigger, steel guide rod, and maybe a few other improvements. They market it as basically a sort of upgraded CZ 75.
The CZ 75 SP-01 Shadowline is like a CZ 75 SP-01 Shadow, but with the above mentioned upgrades (thin safety, nickel trigger, steel guide rod, etc) as far as I can tell from the CZ website.
So, CZ makes a bunch of models called the CZ 75, and the options "package" for lack of a better word is the difference between the SP-01, non-SP-01, Shadow, Shadowline and base models.
Hopefully that hasn't confused the issue more!
PS - already into glass three of a local microbrewery dark IPA, so I'm blaming that if I made any glaring errors here.
For what it's worth, I absolutely love my CZ 75 Shadowline (identical to the 3rd pic the OP posted). Have put thousands of rounds through it and it has never had one malfunction. My friends kid me, because I tell them I'm not cleaning it until it has a malfunction, and it's been probably 3000 rounds since the last cleaning. It's a solid metal pistol in a time where most are at least part plastic (and I own my share of plastic ones, too, they have there place in my safe) and it just feels nice and solid and "heavy" in a good way, with less muzzle rise compared to a lighter gun. It's my favorite pistol.
