RE: Good Second Plane?
Reading the other part of your post, about the Cub-- make it your 3rd plane. Learning the tail dragger stuff on another plane will make the Cub a great 3rd plane. I have a 1/5 scale Cub and it's my favorite. The thing about Cubs is, you have to fly it all the time; it's like an older style car without power steering or brakes and 3-on-the-column shifting. A Super-D like tIANci said is a good plane, but much more high perf than the Cub, a good 4th plane. If I had to compare (I've flown R/C versions of the Cub and Super D), I'd say the Rascal has the best attributes of both without the bad habits.