The MagPul QD swivel is only made for the 93B. See their website for details. At one time the made a QD swivel for a single point sling, but I haven't been able to find out if its still available or not.
To mount the swivel, (you have to order the part the stock doesn't come with one,) you remove the two reinforcement plates and screw the swivel in place. It comes with the screws to do that. The screws connect to the plates, not the stock. They are sold in singles, so if you want a QD swivel on both sides you have to buy two.
I'm not sure how you'd mount a QD swivel on an A model. But call Rich or anyone else at MagPul and I'm sure they can tell you how to do it.
I run a KAC QD swivel mount on my LaRue handguards, and the QD swivel on the stock with a CQB Solutions 3 point. (Now Specter Gear)