Finally clenched my teeth around the speeding bullet (what does biting the bullet mean anyway?) and bought ODAC+O2 DYI parts from Head'n'HiFi. Received a Chupa Chups cola lollipop for free too, lovely. Built the thing during two evenings at work. Accidentally mixed up two groups of 4 resistors each, fortunately I noticed when I was about to install the second group. I got angry at myself and would not allow another mistake, and the thing passed all tests with flying color after I had finished. Too bad OpenBSD does not support rate matching hubs, I might look into that, but the combo did wonders to the sound on my MSI with Windows. I had the impression the built-in audio is pretty good in an MSI GT60. Not very. Very happy I bought this thing.
Time for supper, at 22.32... Testing, verifying, and figuring it why it didn't work in OpenBSD took some time :p
EDIT 2016-02-06: It seems that this is one of my most interesting posts, quite a few page hits. Just to let new readers now, after a few months of use, I'm still very happy with it, it sounds very clean which I like. Since my Denon AH-D2000 requires very little power, I tend to run it straight from the ODAC and I control the sound volume on the PC. Which is herecy of course, but together with Meshuggah, Perturbator and the like, this setup provides plenty of material to bang my head through a table to. Works quite well with violin concertos or Bach partitas too. I want a Stax setup.