Personally I'd call amain and see when they plan to get these back in stock...
http://www.amainhobbies.com/product_...-Digital-Servo
There isn't anything better for less than 50 bucks unless you are willing to risk Chinese. Hobbypartz has a good EXI servo. I'll link it if you're willing to give it a try, it's 14 bucks, IIRC.
To use the high voltage you'll need a bec.