Hi Wolf and welcome to the forum.

having lived in the Netherlands for 14 months (August 2007 to October 2008) I have an understanding of what it's like to live in an apartment and have to deal with neighbors in close proximity. So first off don't discount "bookshelf" speakers, just put them on a pair of good, solid stands and you will be very surprised at good a decent pair of bookshelf" speakers can sound. I was using a pair of nice Energy Veritas 2.1 speakers on a pair of dedicated stands and they sounded great. I would not consider floor standing speakers unless your apartment is on the ground floor since floor standing speakers (and subwoofers) tend to vibrate the floor more than stand mounted speakers.

Next I would consider getting a nice integrated amp (Cambridge Audio makes several very nice and reasonably priced units) with a reasonable output, in the range of 50 to 100 watts per channel. A very simple system but one that can be purchased in the Netherlands for a reasonable amount of money.

You may want to consider the LogiTech/Slim Devices SqueezeBox system since these units are readily available in the Netherlands.