Let me make sure that i understand all this.

These are the components i would need? : Robart 510RS 90degree Mains robostrut ready, and Robart 653 Robostruts ( Left and Right)

Do i still need the 90degree Mains Wire? or is that what the Robostrut is replacing. OR does the 90deg Mains wire go inside the Robostrut?
Also il purchase the variable rate valve as suggested.

Sorry for all the misunderstanding i just want to order everything i need in 1 shot, and as i said ive never done a retract system =(