Here is the official word, from PRS, I emailed customer service regarding DS-O1 and DS-02:
----The Starla model was released first with “Starla” pickups, which were later used in the bridge position of the Vela. Later, we slightly increased the output of the Starla pickups, but retained the lower-output on the Vela bridge pickups, hence the difference between DS-01 and DS-02. The DS-02 is the second variation (slightly hotter output) of the Starla pickups.
We currently don’t offer the DS-01 or DS-02 pickups for individua sale. I’m sorry for any inconvenience this may cause. Let me know if you have any further questions and thank you for your continued support of PRS Guitars.
Ryan
-----PRS Customer Service & Tech Support