As far as I know, Creative Sound Blaster Audigy 4 has been tested on S5000PSL, model number 70SB061000000.
Success!!!! Just wasn't holding my mouth right I guess, but a friend has mentioned to me about re-inserting the card several times to clean the contacts on the board, and now it works. Went with one of the original Audigy 2 cards, in particular an Audigy 2 ZS, all systems are nominal. Even managed to get the little front audio panel that goes with it.
This machine is ready to go whoop some tail in Unreal 3 now.