Oh man, I just finished spending hours trying to ID ALL of the different varieties and here you have it all at once in a single post! I have even managed to find photos of all the units online (that was not easy).
I must admit that I am completely confused with regards the "fog"/"no fog" business. These all have 5 lenses and I really have no idea what the fog light is or even if my current unit has it (or not). My owner's manual says nothing on the subject. But as seen below, it does ID each panel and the bulb/watts used.
From this I am sure there are no dual filament bulbs since there are only 1 kind of socket and 2 kinds of bulbs in place.
I have looked at the parts diagrams/listings
here. This mentions only some of the units on your list above. And one is a Hella (1234669). This can be seen
here. They also reference another Bosch unit (123585) that can be seen
here. At least at a glance, all 3 of the parts shown "look" the same in that all have the same reverse light position. Not sure about the brake though.
Then there are the remaining options - both Hella and Bosch - that swap the reverse and brake lens positions. The Hella (1235200) can be seen
here. And the Bosch (1235589) can be seen
here (at least for now).
I am sure I can live with any of the above units (including those in this last group with the smaller and relocated reverse lens). And would do so if I can get them at a more reasonable price than the crazy expensive US ones. But my concern is about form, fit, and function.
I have recently found this listing for the wiring harness that feeds the tail lights. Seems to be item #1 (1324917) shown
here. As I only see this one harness listed I would hope to conclude that this will indeed plug into and work with any of the tail light units above. Maybe not true but I don't know what else to conclude. Regardless, as long as the plug connector fits all of the tail light units I am sure I could move the wires around to get everything working as expected. Even this would imply that there would be different wiring harness numbers and again I don't see that.
That would seem to leave only the gasket as an issue. While quite similar, the Hella and the Bosch seem to be different enough that there are two part numbers (Bosch 1235595 and Hella 1235167). So it would seem the gaskets are not interchangeable. This makes me wonder if the fit of the tail light assembly against the body might be any different? I cannot imagine that Volvo would employ two different body panels just to support two different tail light vendors or even USA versus elsewhere. This is especially true given that there does not seem to be multiple wiring harnesses - since those would seem far easier to vary than body panels.
Sorry for all this lengthy text. And thanks for your help and reply. I just need to be sure of what I can safely purchase because all of the options are still pretty expensive, special order, with long waits for delivery, and no ability to return.
Cheers!