ON 40-60 sized planes I usually use the metal rod in the tube and put several anchor points to prevent flex. Larger planes is all direct linkage hook ups as short as possible ,pull-pull on the rudder if the extra tail weight is not needed.
Heres one thing I do ,at your LHS they should have the metal rack I use round alum tube thick walled ,if you can find the correct size a 4-40 tap will make perfect threads.See the example below.Couple the clevisand rod useing a short piece of 4-40 threaded rod a drop of thin CA will insure it never to come unscrewed .