Daceon
I don't fly the Spit much either but I find myself flying an aircraft based on the time period and location I find interesting. I started flying the Spifire Mk VIII in Asia because that was what I was interested in. I do find myself flying the Mk VIII the most because of its use in SE Asia, but I also enjoy the historical aspect of it. It is the final development of the Merlin engine models and its airframe led to the griffon engine models.
From a historical point of view: the Spitfire Mk V was the first Spitfire to be able to handle negative Gs without the engine cutting out due to fuel not getting to the engine, so this may be an option. And then there is the Mk IX which is a Mk V airframe with a more powerful Merlin engine. All of these would make a fine intro to the Spitfire. After flying one or all of these, going to the griffon engine marks should be rather simple. That does not mean easy as you will develop habits when flying. These habits should be okay when you transition from merlin engine to merlin engine marks but these habits will cause problems when you transition to the griffon engine. Example, the griffon engine rotates the propeller in the opposite direction compared to the merlin engine. I don't remember which but I think the merlin rotations clockwise and the griffon rotates counter-clockwise. I have read pilot bios who almost lost control of their griffon engine aircraft during take-off because of their merlin engine experience.
Anyway, fly what interests you, you will master the Spitfire with time.