I'm sure you will get all sorts of ideas and opinions from folks that are genuine PT-19 and Space Walker enthusiasts.

I would prefer something somewhat large with a good wing loading. In my opinion, either a Four Star 60 or a Tiger 60 are both ideal for this. They are both easy to fly in a sense that they behave somewhat like a trainer, yet have the agility to behave like a beginner aerobatics aircraft. In fact, when I was contemplating getting into Pattern, my instructor suggested a Tiger 60 because it was capable enough to do all of the entry (Sportsman) level aerobatics - rolls, loops, cuban 8, immelman, and so on - maneuvers, understand that these are not 3D maneuvers, but basic aerobatic maneuvers. They also very forgiving to mistakes, and will come in slowly enough see what's going on, yet a bit faster than a trainer.

I am not knocking nither the PT-19 nor the Space Walker because I've flown both. But for a good, reliable, and capable second plane that is also tolerable (meaning not something that will drive you crazy with instant stalls and so on), they are both worth considering.

My Tiger 60 had a Super Tigre 75 engine and would do just about anything I asked of it. I am not (never was nor will be) interested in 3D so this was a perfect choice for me.

CGr.