I managed to buy it here: https://store.playstation.com/en-us/...DLEGACY0000001
Log out if you don't have a US account else it forwards you to your region and a dead link.
I had to create a US playstation account, it was a lot of messing about. But I did notice when I downloaded it on the PSP and logged back in with my UK account it was still playable.

If I want it on my Vita I need to mess around with a second memory card unless as you say I jailbreak it.