If I were you, I would go with a boa. They are likely going to be cheaper than sd retics, and are the exact size you are looking for. I have also heard that sd retics are very aggressive.
BTW, you mentioned that people seem to change during their teenage years. Research has shown that teenagers brains are still developing, especially their frontal lobes, which is their decision making part of the brain. So, it is true that teenagers do change.
Yeah. I just don't want to admit my personality and likes/dislikes are changing... I just can't ever see myself without snakes within my top 10 priority list.