ideal combo upgrade (carb + big bore + cam)
 

Trying to decide what will be the best combo upgrade for these different big bore options.

61mm, 62mm, 63mm

Safe to go with a 30mm carb for all three?
A9 cam?
Wouldn't hurt to top it off with a 4 valve head?

Plan on doing the upgrade on a 150cc gy6 scooter.