The difficulty with trying for a long sample is that it would be very hard to track down the necessary translations for it (assuming new enough to still be in print or old enough to be in public domain), especiallly in e-book format, as well as archaic language reasons (especially with public domain translations, which are often stilted in character due to generally being at least a century old).
I'd suggest that rather than War and Peace, perhaps try looking for samples of a popular, modern international bestseller, such as one of those inevitable thriller novels like The Da Vinci Code, which is bound to have a large amount of modern language translations, some of which you may be lucky enough to find first-chapter samples of online at various vendors and/or publisher websites.
Failing that, I know the Asterix and Tintin comic book adventure albums have all been translated into upwards of 30 languages each and seem to mostly be in print (though may be difficult to track down).
ETA: Your best bet for an e-book available modern language text with lots of translations may be Paulo Coelho's The Alchemist, which Wikipedia says has
67 translations, some of which Coelho himself released to the internet at large and encouraged people to download, compared to TDVC's 40 or so, and Lord of the Rings' 38.