I will totally let all of you know what I am gonna buy! I hope I get the money for the presonus one back soon, I think I will get the Focusrite 8i6 then, because in Germany it's like 235€ and the 6i6 is 245€. I mean I get two more inputs with the 8i6 that seems to be a good deal. Anyway one stupid question at last:

On the Focusrite Website it says this Interface has 8 inputs? But actually there are only the 2 on the front, the 2 on the back, MIDI In and this weird thing called SPDIF (I googled that one...).
Damn I am **** stoked that so many people on here posted in this thread, really nice! I will keep you updated and do my homework with Stereo/Mono sound!