Personally I like the servos mounted on the stab, that way taking the stab off is simple and does not require unhooking the control linkage.

Second point, I see in your pic you have what looks like a JR DS9411sa. In my opinion that's WAY overkill for the rudder on a pattern plane. Also way too much weight. I'd suggest going with the [link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=JRPS3421SA]JR DS3421sa servos [/link] which will save you 1/2 oz. They're about the same speed as the 9411s, actually .01 sec/60° faster

I've used these on two different planes with excellent results.

These smaller servos may also give you additional mounting options given their small size. I mounted both of my stab servos with the servo on its side, but I've found that this limits the throw that can be used since the arm will drop into the servo recess when throwing to the extremes. Because of this the next time I do this I'll probably mount the servo perpendicular to the stab (like is normally done with the aileron servo). This allows more throw without bumping into the wing surface.

Keith