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.