Basically it would appear that the rule of thumb is that the more electrical extras (windows, mirrors & rear wiper) the van has had fitted in the factory the less extra parts you will need to upgrade the van to cruise control and vice versa.
If you have the "full house" of OEM extras fitted then it's just a case of getting the cruise control stalk/loom (make sure it has the plug in connector), whipping the steering wheel off, changing the indicator stalk for the replacement one, reassembling and then getting the cruise option turned on within the ECU using VAGCOM.
Not quite sure how much of this correct I have a pov spec t5 manual windows no rear wiper as it was a panel van. I rang the dealer to check if cruise was able to be fitted and gave him the chassis number and he said yes just the stork required but would double check with the workshop but aparently my van has the electricery to just plug it in.
I get the impression that sometimes you won't know for sure what can be done until the pro gets his head under the dash for a look. I think the general rule is that if you have factory fotted electric windows and mirrors then you have the electronic jigery pokery to just get the stalk wired in. If you don't then it requires a module in addition which doubles the cost pretty much. The Hazzy Dayz website tells you.