From what you described, it sounds like a decently sized tattoo. As far as placement goes, it is really up to you. You could go with a upperback/shoulder blade, or (my favorite) thigh.
I have a cherry blossom branch on my right forearm, its a fairly large piece, it is in memorial of my friend who passed away in a car accident, she was 17. I also have a butterfly on the opposite wrist, its sort of an optical illusion because the wings are also skulls, most people only see one or the other.