Hi,
Thank you, I will try the relay and have no question about that implementation, but the second response opens me new questions:
I wrote about relay because my motor is 12v and around 2A because I don't know what transistor to use to implement the switch and the best schema for it so not to get it hot, etc. in terms of a safe design, could you please suggest?
And yes: this is a question of safety, 2 motors will turn the head up and down, left and right (installed vertically to each other) and I am trying to approach full guarantee that no movement will happen out of expectation, specially 'when something goes wrong' based on "if something can go wrong, will go wrong", but again, we have another from Murphy: "if all seems working correct, something is wrong!" 
May only Arduino help to be sure that motors never go out of control 