If you are aware of Indigo Prophecy being sold, but you specifically want Fahrenheit, then check this out:In 2006, the game will be re-released in Canada and the USA under the title Fahrenheit: Indigo Prophecy Director's Cut. This version of the game, available only for the PC, is uncensored and rated "Adults Only (18+)".
From the wikipedia article.
So if you want it for console you're going to have to get it imported. They do have it on amazon but you have to go to the UK version of their site.
Alternativley go here
(it's Australian so you'll probably get a good exchange rate), or here
for a UK site.