Yeah if you have RNs I'd get the one linked in 1st post, ebay Germany is cheapest.
You're original FM cable stays for FM, but you'll need a 3 new cables for phone, GPS, DAB if you want all 3.
I think the other FM for diversity comes from somewhere else, under seat or hatchback? haven't come across it yet. You'll need an FM dual fakra conversion lead at head unit end about £8 ebay.
I still have the window DAB stick on one, if someone wants to pay the postage, you can have it and try your areas signal....
Fitting in 5door was really easy, just don't force the headling too much, but it will bend enough to get the cable under, just remove the airbag plastic labels on pillars and the screw underneath. Worst bit was working upside down on the aerial and disconnecting the old FM cable, a mirror might help, but in the end I yanked on the white plug with some pliers and it came free.