Building A Simple R/C Plane

I have a very simple Air Hog F-16 Falcon R/C plane. Basically, it's just a small styrofoam plane with a small motor and fuel pack, which connect to two propellers via a wire. The make is basic enough that I'm wondering if I can buy these parts seperately at a hobby store and attach them to a much bigger styrofoam glider that I have. The RC plane is 14 inches long from nosetip to end, with a wing span of about one foot. The plane I want to modify is 18 inches long with a two foot wingspan. I'm new to RC planes, so I'm not sure the difficulty level involved in this (looks simple enough, though), or what size motor/propellers/fuel cells I will need, and how expensive this would all be. I also considered that the materials would have to be compatible with my current remote and charger. Has anyone else here done something similar? Any comments, suggestions, thoughts? Thanks.