My humble opinion is, you should take the money you would spend on leasing or buying and put it towards lessons or your two year old. Trust me by time he is three you will be wishing you did. Send him to a trainer now and they can work on the basics? So by time he's three you don't have to waste your time getting him desensitized to saddles, bridles, the trailer, there are SO many things you can work on!! and SO many things you can spend your money (your parents money) on.
What about when you go to college? What are you going to do with your horses? Trust me you can't just bring them with you! And if you do it's very, very, expensive. I'm having a hell of a time right now trying to balance money, time, and college. The sad this is I only have one horse. It sucks but you can't, can't, just live for the moment, you HAVE to and NEED to think about you're future and the future of the horses.
Right now you sound like the girl off willy wonka and the chocolate factory. The one who wanted it all? Does that ring a bell?