The winding is not different on our DC pickups, but the cover for 5 and 6 strings are the same size, so if the bass is a 5, you'll need to make sure they know it's for a Roscoe (Nordstrand has all of the necessary information to make them correctly). Jay will definitely take care of you on the pickups.
The OBP-3 is available with the stacked treble/bass and push/pull midrange, we kept that in stock at Bass Central when I worked there, so I'm certain that any Aguilar retailer can get that for you.
