I used Sam's installation as a guide on my RV6, but used the same components (tube dia etc.) that are used for the primary aileron controls. Here is a list of the parts that I ordered from Van's Aircraft.
AT6-035 X 1 1/8" X 6 Feet Push Pull Tube
VA-111 Female Rod End (W-416) (qty 2)
Bearing MD3614M 3/16 X 3/8 Rod End (qty 2)
AN316-6R Nut Thin Jam (qty 2)
Washer 5702-75-60 Steel Washer for AN3 (qty 2)
As far as the final length of the servo push tube, you will have to determine the correct length when you have everything in place. Hope this helps.