csisfun,
You're probably making a good decision to go with a biplane if you are not experienced with "heavy" models. Lighter planes takeoff and land more slowly, and are generally easier to fly. Lowering the wingloading by adding a second wing is a good way to go. I'm including a couple pictures of small airplanes I designed and built to give you a little encouragement. The biplane has a 23" wingspan and weighs about 13 ounces. The low-wing sport plane has a 32 inch wingspan and weighs about 12 ounces. Both fly very nicely.