I tried to find Recaro seats for my V sedan for the entire nearly four years I owned it.
The seats are not available for new purchase anywhere, not from GM, not from Recaro, not from anywhere. Recaro designed them, Lear (the same company that makes the stock CTS seats) makes them. Give up on new parts now, they do not exist outside of the factory.
There are seats available from crashed Vs in various junkyards/pick-a-parts. The seats are direct bolt-in. However, to make it truly functional, you must also have the center console pieces appropriate to the Recaros (heated and cooled seats as opposed to the regular seats, only heated). It is pretty much a full-time job to find the seats and snatch them up before someone else does.
The easiest and best way to get Recaros in your V is to trade it in, which is what I ultimately did, and it was a good decision--those Recaros are pretty darned good!