Tony:
It is wonderful that you want to witness to your crucified Lord by getting Him tatooed on your skin. But personally, I believe that Jesus would rather have the world see Him in your life and in your actions and in your heart. There is an old Protestant song that I remember from my pre-Catholic days, “Can the World See Jesus in You.” That is the key, in you not on you. Jesus needs to be a living force in your life, not art on your body. I could be really wrong here (and I often am), but I feel like tatooing Christ Crucified on your skin somehow trivializes His sacrifice.
I know that you intend to be a good Catholic all your life, but what if later in life, you leave the Church and fall into a life of sin, what witness would that give to Jesus on the cross tatooed on you? Or what if you become a Protestant where crucifixes are not respected and God forbid you become ashamed of this tatoo of Jesus on the cross?
I admit that I have never really understood the attraction of tatoos, but this sounds like a really bad idea to me. Please pray and consider carefully before you do this.