Sidepulls?

I own a almost three year old, which I've ridden about the grand total of 5 times. I have a O-ring snaffle for him, which I have ridden him in 4 of the 5 times, and he never has nescessarily repsonded well to it. He chomps on the bit and seems to like it, but I don't believe he understands what I'm asking of him when using the bit.
So today I proposed to my sister, who was helping me with him, that we try a hackamore on him, which we did. He responded EXTREMELY better in it compared to his snaffle. I did some reading up on hackamores once we finished riding (I've only known one person who ever used a hackamore regularly, and really have never used one myself intill now) It sounds like a sidepull would be a good thing to invest in for him? If so, what kind would you suggest, and would I be able to do any local showing or playdays with him in it? Also, would it be a good thing (if I continue with the entire hackamore thing) to eventually move him back up into his snaffle?


Thanks!