They are the stock Seymour Duncan pickups. And yeah, I also struggle with keeping that Bigsby in tune. Try putting a little bit of graphite from a pencil into the nut slots under the string. This allows the string to slide back and forth while the Bigsby is getting used without the string catching or getting caught. This seems to help a bit, but honestly I haven't found a surefire way to keep that thing completely in tune. Keep your tuner handy, and tune up in between songs or whenever you get the chance!!

Keep rockin'!!