Hi Jax,
Providing the rudder is not a huge one, which I doubt it will be with an overall length of 510, and the model doesn't weigh a ton a good Mini Servo will do very well.
I tend to use the metal geared versions of these in most of my models, the latest being a 900ml Tug with a fairly large rudder. I get mine from Hobbyking for about £4.85., I've filled one with water by mistake but never burnt one out.
Cheers.........Ron