Dr.Weasel,
I am assuming that you want to use the product engine that came with your Cub for power. If so, check out the Brodak site listed above and look at their 1/2A airplanes designed for a "radial" mount. This will be the ones with the flat mount on the front. The ones with a forked front-end are for "beam" mounted engines.
Another "radial mounted" plane is the Skyray from Sig Manufacturing. It has a sheet balsa wing and is easy to build. If you have not built models before, this would be an excellent choice.
When you mount your engine you must make a choice: to buy a tank and backplate that fits on your engine or modify the existing mount to use your engine (assuming a Sure Start engine) and adding an external tank. If you do either of these, come back and ask; we can supply you with information on how to proceed.
If you opt for a larger plane, let us know what size and someone will be able to help. Generally, the smaller ones are harder to break but also harder to fly. Since you already know how to fly, you have more options.
Are you still in Scouts? This is my 23rd year with the BSA.

George