Eddie,
Why not just apply 4oz fiberglass cloth on forward and aft fuselage foamcore sections and 6oz on the center fuselage section as i did on my Super Constellation model. If you want, you can double layer also without any weight penalty at all. It has worked for mt model that weighs only 25 lbs RTT at this time!....think about it. I couldn't be bothered by adding balsa skins on both forward and aft cone sections of fuselage of my Connie, so this layup worked out very nice n super light. My wings are directly glassed over foam also.......
http://www.youtube.com/watch?v=bD3g-Y9m5UY
You can then burn out foam also if you like just the fiberglass shells as this is one off model i imagine....