I've read a lot on the forums already and got the DT 990 250 ohms as my first "higher-end" headphones. Their sound is really great compared to my other headphones even when I drive them with my Xonar DG soundcard or just the built-in output of my Macbook Air. Sometimes I get the opportunity to listen to my cans using the headphone out of a Pioneer hifi amp and I'm starting to get the feeling that I'm missing a great deal of the sound because the outputs of my computers are not that great.
So in short, I would like to get a headphone amp and most likely also a dac to bypass my internal hardware completely. A better sound card like the Xonar Essence wouldn't help me that much because I would like to have a setup I can also use with my macbook. It doesnt have to be all that portable but I wouldn't want to be like tied to my desktop. I've already read some recommendations but the problem is that I live in Germany where it's hard to get some of the good hardware. I don't feel that comfortable with shipping 200 dollar hardware across the Atlantic, also because the shipping costs are insane.
My budget would be around 200 euros for both the amp and the dac if that's even possible.