I would strongly suggest a different option. I have helped a few kids who have put it off to this point too, and it isn't going to happen. You would have to work a ton on it to finish it, and you can't fly a P-51 for a first kit, let alone build it.

If you seriously want to do one on RC planes, then get an eagle II from goldberg or something like it, get going with someone that can help you asap and you may get it done. You will need to work on it at least one full day on the weekend, and at least 2 to 3 full nights during the week to get it done. If you want to invest that much time and energy, go for it. If you can't commit to it, forget it. Its not going to finish itself and if you don't put 100% effort into it, you won't get it done.

Don't mean to blow your thoughts on it, but I have seen it too many times and I am not going to sugar coat it.