The dowel setup to me is a little sloppy. Its OK for a trainer but I wouldnt use them on anything else.
Something like these
http://www2.towerhobbies.com/cgi-bin...?&I=LXD856&P=7 is much better. They are easy to install and to me are a lot more practical. You have to brace them every few inches but they give you a little flexibility in case its not exactly a straight shot from the control horn to the servo.
As far as the steel rods just make sure they are heavy enough and wont flex under load. I would think that a 2 56 rod would be fine on a 10 size shrike as long as it is not too long.