I seem to recall from another thread that you said you are still living with your parents. Please take into consideration that you will probably still have this animal when you go off to school or to work or whatever. These giant snakes are really difficult to move, hard to find places to accomodate, expensive to keep once you no longer have your parents' support, and difficult to rehome.
Also remember that giant snakes are genuinely dangerous animals and you never want to be in a situation where you are feeding the snake or cleaning its cage without someone else there in case of emergency. That may not be an issue now, but what about a few years from now?
I don't want to discourage you from keeping big snakes, just be sure you are thinking of all the necessary issues, and not just how much you want the beast. If I were you I would start with a more manageable mid-sized snake like a redtail or yellow anaconda.