I believe you originally stated a somewhat scale "war-bird", then somehow the cub got mentioned. If you fly in an area with crosswinds, the cub is not a good second airplane, It weather vanes and tip stalls easily, compared to your trainer. There are several threads on the cubs bad habits. If you want that type of plane, a Decathalon or Citabria has similar geometry, but has washout in the wings, to elimate the bad stall characteristics of the cub.

If you are just moving out of your trainer and want a low wing, scale like plane, the World Models T-34 Mentor is a decent second airplane, has a tri-cycle gear and is very aerobatic as well. Seen many Newbies very satisfied with this plane, some for a couple of years.

Good luck on your search for that second plane!