To get PS1 visual novels, you can start by looking on auction websites. But be careful and check the seller's reputation. You might also consider reaching out to local gaming groups or clubs. They may hold swap meets or know of reliable sources for obtaining these older games. Additionally, some larger game retailers might have a small section dedicated to retro games, so it's worth checking there as well.
In GTA Liberty City Stories on PS2, getting a helicopter can be a bit tricky. One way is to progress through the story until you unlock access to them. Another possibility is to discover hidden helipads as you explore the game world.
You might be able to find it on the official PlayStation Store for PS Vita. Just search for it there and see if it's available for purchase and download.