Another good way is to use a matched pair of servos but with one of them reversed. JR offers the ST47 and ST47 Reverse (JSP20050 & JSP20050R). These should do the job if you are willing to pick up a pair,
http://search.horizonhobby.com/index...d=11ED1B04ABC3 shows both. The reverse costs a bit more due to the lower production volume would be my guess.

These on the end of a standard "Y" should do the job.