Got back info from my audio pro friend. I explained the exact kind of recording you want to do on the audio front, and he said that this solution here
is by far the best price/performance item you will find. It does cost around 700€ in the EU though.... He told me he'll look around to see something a bit more affordable, I'll get back to you again. Busy guy so I can't push him....
EDIT: He is also telling me that this recommendation is only if you really need full multitrack recording. He is asking me whether you need / want to record separate channels for everything or if a good stereo recording of everything is enough?