Those are all newer ones. The best chart I know of is
this. I wouldn't necessarily call their testing methodology perfect, but it's the most comprehensive chart I can find.
Chromix sells a lot of displays and colorimeters. You might try asking them regarding the Spyder 4, as they seem to do some testing of combinations.
Anyway as far as I know, the hardware in terms of color filters used is basically the same for a given brand assuming a current model. What I would avoid is older stuff. This means I would not buy a Spyder 2 or 3, a DTP-94, or an i1 display 2 today. Also watch out for X-rite's weird use of the colormunki label. The colorimeter is the colormunki display, and it is more recent, so it's designed with wide gamut as well as LED backlit displays in mind. Most of the upselling on price is related to software, and if you read through the documentation, they will mention features supported. Also as I mentioned before, there is no real way to hardware calibrate an imac. If you switch to bootcamp, none of those settings will be retained, as the instructions are stored in OSX, not within the display hardware.
I kind of wish I could provide a better answer, but I haven't tested each of this individually on the display you're using. I can just say that the ones you're considering are new enough to be appropriate considerations. Just make sure whatever you buy supports whatever software features you require. Some of the less expensive versions don't support things such as trying to correlate 2 displays, even though that is at a software level, so you just have to read a bit of documentation.