RE: Sig 1/5 scale piper cub
Built one many years ago. It's a builder's kit, lots of stringers and stick wood. However, it can be built VERY scale, and it's a great looking/flying model. There are no bad surprises. Just take it slow, read each step thoroughly and you'll do fine. Don't overpower it. A .45-.55 4 stroke will be great, and will fly it in a scale-like manner with a large diameter/flat pitch prop.
Warning: Sig has the capability to shrink balsa when packing. Once the parts are removed from the box, they will NEVER go back in!!!
Dr.1