Thanks!
Itll be a less rewarding PITA doing dualzone than the DSG so Im not going to bother. You will required the complete airbox assembly, sensors, AC pipes most probably, additional flap motors quite possibly, Custom wiring loom (on such mods I do it in situ), Climatronic control panel, system regas. Id estimate £300-500 in parts,components and install materials.
Used colour clocks are 250-300 mark but extremely rare. Dealers will be 450ish + VAT and want your old clocks back too.