LOTS of Stars on GB, Auction Arms and guns america in many conditions. Have a Star model BS which is the same as a "B" but with mag safety interlock. BKM would be the same but alloy frame.
Magazines are pretty much model specific so make sure you can get one for a reasonable price. IE B mag does not work in BS etc. Robertsons seems to have the best overall quality ones out there. You should be able to get a nice one with extra mag in the $350 area.