There is already a thread concerning the A6M3 and Ki-43, both good ideas to add to the game IMHO.
The 22 was the exact same as the 32 model, the only difference being the in-wing tanks and the ability to carry two drop tanks under each wing. Both models had the supercharger and it was the same airframe.
Edit: 22 was a souped up 32 
The Models 32 and 22 actually had two entirely different airframes, so no, they were not the "exact same."
The Model 32 had clipped wings. This improved the rate of roll, but rate of climb, range, and maneuverability all suffered. The Model 22 reverted the aircraft back to the same airframe as the Model 21, (our A6M2) but retained the engine of the Model 32. This restored the range, maneuverability and climb. However both versions featured the exact same engine.
This is what the different model numbers meant when identifying the Zero: The first digit indicated the airframe, the second was the engine. So in the A6M3, they all used the same engine but the airframe was different between the two models.
Of the two, the Model 32 would offer a more unique aircraft, both in handling and performance, than the two Zeros we already have so would probably be the best choice.