Krebs Custom just introduced their new Ambi Enhanced Safety for the AK-47. This safety has an extension that allows left handed shooters to operate it with the thumb on their strong hand. Right handed shooters can operate the selector with their index finger or using a standard technique. The Ambi Enhanced Safety also features a bolt catch notch that can be used to manually lock the bolt open.
The Krebs Custom Ambi Enhanced Safety is compatible with both stamped and milled receivers. Check it out at Krebs Custom.