Internal S/PDIF connector on Gigabyte Z97 motherboard
Solution 1:
Now I've had the motherboard arrive I can answer this myself - yes it does work :) Did exactly as I hoped above, just plugged a jumper onto the S/PDIF connector on the board, ran it outside the case and to my surround sound system and Windows 7 was working properly with 5.1 sound immediately after install :)