Sweet deal!
Any annoyance like the door chime or lock honk can be disabled via vag-com tool ($300) Plenty of VW/Audi kids with them around town than do mods for a 6pack.
As for the HIDs it is fairly simple if you can locate the parts cheap. Ideal would be to find a wrecked A4 with them, buying them OEM will cost 1-2k easy. If you get your hands on a set all youll need is a highline module, wire kit/harness and a couple vag-com mods and the rest should be plug and play.
How to:http://forums.audiworld.com/a4b7/msgs/93217.phtml
Please only use OEM parts, no cheap ebay/knockoffs please please please.