I saw the games are available on the PS Store and its japanese 

It should be playable cause its available on the vita Ps Store it self    thats what i know from reading some article on the net
I see.. im on Asia PSN.. Like that i need to register a new PSN account to download it from there?

Yeah man,

I bought PS Vita solely for PS Classics.

And the rest of the games will come later.

well not to be a jerk but to be frank, I won't be buying US PSN cards from you. Amazon is selling it at 1:1 conversion rate(means they sell $10 card at $10/$9.99 to be precise) and sometimes throw in discount, it's going to be hard to match that.

If you can venture into Europe or Japan PSN you may got a shot there, I don't know any source that sell those cards without ridiculously marking up the price.