Another pair of plane that might work for learning to fly a warbird might be a Sig Astro Hog, set up as a tail dragger, or the 4 Star.
The Hog is a fairly inexpensive kit that could also be weighted down to match the wing loading of the Spit. One change would be needed, replacing the strip ailerons with barn door, not really a big deal there. I don't know what the wing loading is you your Spit, the Hog has an area of 824 square inches with a semi-symmetrical wing and a flying weight of between 7 and 7.5 pounds.
The 4 Star, on the other hand, has a wing loading of 18oz/sq ft, a shorter span and is designed as a tail dragger. Again, you would have to change from strip to barn door ailerons
Either one, after being ballasted, would probably be fine, power wise since they are both 40 sized aircraft.