I've got a MK3.5 Caddy (2012) with the basic plastic steering wheel. Being plastic, it has a tendency to get sticky in wet weather. Very unpleasant, but it seems to be standard practice with plastic wheels. I could find a leather wheel of the same style and fit the airbag, I think. This would mean getting a wheel out of a MK6 Golf or similar model.
However, my favourite Volkswagen steering wheel design is the non-R one from the MK7 Golf (and other models) as in the picture.

What do I need to know about fitting this style of wheel? Does it have to come from particular model(s) to work in a Caddy? I've seen the same design ranging from Polos to Crafters but I'm conscious they might actually be different sizes depending on model.
I'm not overly concerned about getting a multifunction version with buttons, but if I did - how would the fitting process differ? What additional parts would be needed? If one came up at the right price I might spring for the MFSW version, but it isn't a priority for me.