Cruise Control - Retro-fitting to a Clio

[RDE]

I'm idly considering a Clio II Phase 2 dci at the moment, but am quite a fan of cruise control. I know many of the higher specificiation Clio II's came with cruise, so wondered if anyone knows if it is possible to retro fit it to a 'lesser' model, i.e. is all the correct wiring there and you just need the steering wheel with the buttons, or is it a lot more complex than that?

It may sound like a silly question, but I understand you cuold retrofit things like autowipers just by changing the stalk on some models, as the rest of the gubbins was already installed.

Cheers in advance.