Ok, some more confusion.
I finally got around to asking the guys what the difference is between those 3 models, and they came back to tell me he 7P6 modules would have problems with phonebook download, so I should go with a 3C8 module, for an extra 60 euro or so...
From my research it looks like the 3C8 module is an RSAP capable module, something I wasnt particularly interested in.
Phone book functionality is obviously important, so Im wondering if anyone here can comment on that?
Have been trawling around the web for an hour or so now trying to find information about incompatabilities but coming up with nothing?
Thanks.