The two I've pull started are the 107ss and the 110 drag. Ignition timing is critical , not too much. It only took one back stroke on the 107 ss for me to buy an electric starter.
The in head compression release would be a good option.
Dyno cams may be able to grind an ez start on the cams , you would need to call them.
I wouldn't recommend any cam with out ez start especially on a mini bike .
Dont know where your at but if in the snow belt look for a tecumseh hm 10 or maybe 8 they are bigger hp to start.
Or even go to big valves on the Briggs engine .
The high lift cams going to be a real painful pull start.