I think you made a mistake. It's g/dm2 / 3.04 > Oz/sq.ft. Correct me if I'm wrong
My scratch built E soarer is in the range of 22g/dm2 (7.2 Oz/sq.ft) and is all composite. By using Lipo's it will be lowered to 19g/dm2 (6.25 oz/sq.ft). These numbers are a kind of ambitious but possible. Work with a weight budget for the whole frame and all separate parts. With the weight budget at one end of the workbench and a precision scales on the other you can get down to 6 oz/sq.ft if you reject enough heavy stuff
Select wood, select your RC gear, select covering. For short: Select everything on it's weight and do a balancing act before fitting the battery etc. You'll save ballasting weight this way as well.