As X-2 is now a somewhat old game, it may be a bit hard to find, but i'd recommed checking gamestop or any local gamestore. Then again, you've got the sure-fire eBay or amazon.
Here you go! All you need is a card that they accept. UK - http://www.amazon.co.uk/Dirge-Cerberus-Final-Fantasy-VII/dp/B000FYQUDW/ref=sr_1_1?ie=UTF8&s=videogames&qid=1278448128&sr=8-1 USA...
No. only final fantasy X-XII are on playstation 2.
Final Fantasy I-II, and IV-IX can be bought as remakes for the playstation
Final Fantasy III can be bought for the DS as a remake
And Final...