As a second plane you may have to settle for scale-ISH. Some of the scale planes which might seem to fit the bill are apparently fairly tough to handle, an example being the J-3 Cub. If I remember right the Stroch is a STOL aircraft with flaps and other special wing characteristic. This would probably disqualify it as a good second plane. True scale for anything military is probably out too. So I would imagine your best bet would be to look at the available high wing (or low wing) civil aviation aircraft.

BTW, I was told that the BUSA Eindecker if build from the kit as per instructions flew pretty much like a trainer. True it's only very roughly scale but still I would be a fun second plane. In a way, I'm sorry I didn't build a stock one in addition to the scale version I did -- which is actually a bit beyond my current flying skills.