Whichever is fine, really! Maybe wait on FF8 if you haven't played many RPG's. It was my second ever RPG and the junctioning system which it uses to strengthen characters got a bit too complicated for me on my first playthrough. I ended up spending most of my time summoning because my characters were too weak. Anyhow, if you do end up playing this game first, just make sure you take some time to learn how it works. It's a great game once you figure that stuff out.

FFT is the best in the series, you might want to save the best for last
If you spend $300 on a PS3 it is only $10
It's not released in Europe, where he lives.

Gameboy advance is pretty cheap now, so that shouldn't cost you much. not sure about the cartridges