I might be of use here. IMHO, go for Blaupunkt stuff. Why? because they design their products mainly for german cars, like yours (mine's a 99' golf IV too... very nice car. Is it your first Golf? have you noticed the great quality leap from the Golf III?). Of course their amps and stuff will work on any car model, but Blaupunkt normally designs their head units to blend perfectly with Opel and VW dashboards. Well, my system setup is full Blau, with some pounds of sound deadening material added all around the car too.
For Tony: VW is not like your normal compact car company. Their factory speakers are pretty good, they only lack a good sub or two :-)
And for the boys/men topic: That's true, indeed. We (guys) never get tired of toys, and that's cool. Girls, that's a different story. They soon get tired with their dolls and then they discover the ultimate toy: guys :-)