Why not just use the Audigy by itself? I see no reason to connect it to your motherboard's onboard sound, it will do everything that the onboard sound can do, and probably do it better.
So if I buy a Aound Blaster audigy 2 nx, and this adapter, http://www.altex.com/product_info.ph...oducts_id=2411
could i not just connect the VIA HII 10k spdif --->adpater in>---toslink (optical) out----->Audigy NX optical in----->corresponding front/rear/center/sub outs? Would that not work?