Heard since years ago that the PSP vers of Metal Gear Solid: Peace walker has release on PSVita.

Feel like wanna give it a try after completed some MGS but cant find it in the playstore (I use Malaysia acc tho) , no PS3 to transfar it anyway, any suggestion on how to play this title on PSV?

Well, if you don't have a PS3, I'm not sure how you can do that.
You can however:
a) Borrow somebody else's PS3 to initiate the download to your PSV
b) Copy the file from someone who have downloaded it to their PSV and have backed it up at their PC
c) Try searching the purchase history of the game from your PSV to initiate the download
d) Google search about it. I've seen on Youtube, there is a trick to whitelist all of the PSP games for the Vita trick through email. Maybe that will allow you to download it.

great suggestion tho, thanks bro Mubarak, need to seek for a ps3...

I have a PSP copy of MGS Peace walker.. U wan?