flystright,

I would go with either the JR ST-47BB or Futaba S3004 (I fly both and can't tell any difference in them). Both these servos have ball bearings on the output shaft while the stardard ST-47 and S3003 have bushings on the output shaft. I've got a few of both with the bushing that have slop in them (these have been regulated to throttle servos). They cost a couple bucks more for the ball bearing versions but in the long run are well worth it. I fly .40 to .60 sized planes on these servos and have had no issues.

Hogflyer.