What green tea has the highest caffeine content?
I have no idea about what the absolute strongest teas are, but all three of the things you mentioned appear to have caffeine and antioxidant ratings here: Gyokuro Imperial Green Tea Jasmine Dragon Phoenix Pearls Green Tea Matcha Japanese Green Tea

I suppose that establishes a rough ordering - matcha is strong, the imperial green is next, and the pearls are last. But I'd take it all with big spoonful of salt; there's tons of variation even within a specific variety, and you can get lots of different kinds of matcha, lots of kinds of tea made into pearls, and so on.