If you plan on moving to low wing planes at any point the Sig Four Stars make an excellent low wing trainer/second plane. Goldberg Tigers also have a big following as a low wing trainer, but I don't think the Tigers come as an ARF, I know the Sigs do. The 4 Stars are excellent fliers and while they aren't 3D planes they'll do a lot of things the high wing trainers won't.

Edit: If you ever had an interest in building your plane from a kit the Four Stars are a great first experience, easy build, laser cut parts, the running joke is pour glue in the box, shake it, and pour out the completed airframe.