"only 9kg" -- well that is heavy to me. How easy is it to rotate the rod really?
For the mechanical side (finding the right, affordable motor) I am pretty ignorant -- I know someone that did exactly that with his router table but it was not with a stepper motor, just a standard motor, up/down buttons and limit switches.
(that makes me think that you will probably need a mechanism to "limit" the movement to not exceed the maximum position range.)
You might want to check the myriads of "DIY CNC" sites out there doing very similar stuff to get advice on the "mechanical" side of things.
You might not need to build new PCBs: there are already lots of "breakout-boards" out there. (Sparkfun/Robotshop)
This is a pretty common thing you are looking for. I guess the solution would depends on how much "fun" you want to put in this