A and C
I think if you got the three of us building a training aircraft you would probably end up with a composite SF260.
Used to look after a SF260, marvellous aircraft, but shame it was Italian, I had a cracked nose leg trunnion and even AOG it took them over 6 months to produce one, the rest of the parts too were a pain to get hold of. The supply to the Military was apparently better, I do hope so.
You could have a combination, the piston one and the advanced Turboprop that went like snot.
As for Pipers and Cessna's as none aerobatic I would have thought they were a none starter, mind you Piper did take the PA32 modified the fuselage and made it aerobatic for the Military, also being tandem seating it would align with the later types the RAF operate and be cheap to run being based on a Piper PA32.
See
ENAER T-35 Pillán - Wikipedia, the free encyclopedia