Cheers guys, glad to see you're liking the build! I finally received the Gotek drive and the 5.25" hot swap bay, both of which will require some modifications to properly fit in to this case with its quick-release sliders, so that's my weekend already planned ahead then.

Yeah the SB16 is a bit on the older side for rest of this build. The thing is, I need it for the native OPL3 support as I don't find the YMF262 emulation to be very accurate at all on the newer cards.
I did run an Audigy side-by-side with the SB16 for Windows gaming for a while, but the motherboard clashed together with both cards and resulted in crackling audio, so the Audigy had to go. Plus it was black, I couldn't have that in the middle of all the green'ness.
Here's a quick sample of the OPL3 sound running on this system:
https://www.youtube.com/watch?v=qhxkKu-l5vII had the bass cranked up a notch too high in the SB16 DOS Mixer, but the FM synthesis is just as crystal clear as I remember it from 1994!
Quality wise the SB16 isn't really too bad even in Windows, it certainly does its job at 16-bits and 44KHz. A newer A3D card would be nice for acceleration and headphone use, but haven't managed to get my hands on one just yet.
Did find an IO-shield from the hoard of retro parts that fit this motherboard, cleaned up the back of the case nicely.