Mk6 is easier and has been done multiple times-I have also personally done it. Requires the wheel and airbag, new steering wheel control module and possibly a new indicator stalk and clockspring.
It's possible to get a Mk7 wheel working correctly but it's more involved and from requires a special version SWCM, new clockspring and some custom made CANBUS decoders for the buttons with wiring changes. There's a VW retrofitter in the UK who does it.