the original sb live value (forgot the number) has digital cd-in header (retail comes with the cable), no spdif out jack onboard (can add daughter card for that).
then x-gamer, mp3+, platinum add spdif out jack onboard.
first oem sb live value is the original live value with or without digital cd-in header,
second oem sb live value is the x-gamer, mp3+, platinum with all plastic jacks instead of gold plated jacks on retail cards.
there are many different sb live variants for oem, above 2 are just some of them.