Body lifts are great, not all would agree with me and we have had the arguments on here before on the pros and cons of BL's. You are 15, you most likely do not have a large expendable income. A body lift is a great way of lifting a vehicle, cheap, and it helps keep your center of gravity lower.
Personally I am trying to avoid the body lift when I finally go up, I am willing to trim body panels however to compensate.
And like I said, find out what lift is already on there. You may be able to raise it up to 6 inches very easily. If the kit has the 4 inch drop brackets for the front axle, then it is possible to put 6 inch coils in there. It also has some added benefits, but there are a few other things that you need to account for like the angle of your steering arms.
I would suggest going through a few of the build threads and the lift sections of the site. There is a lot of info in there that would be beneficial to you.