What legendaries can be caught in white?
Of course you can 2nd answer: the only nonunova legendaries you can catch are heatran, latias (white 2), and latios (black 2). You need to make black kyurem (black 2) but white kyurem (white 2) can't be traded. However, if you don't have black kyurem, you can make white kyruem, but only if you've caught kyruem.
If you're talking about the legendaries, the exclusive one to Pokemon White is Zekrom. You can also catch Kyurem (Giant Chasm), Cobalion (Mistralton Cave), Virizon (Pinwheel Forest), Terrakion (Victory Road), Thundurus (Stormy Route 7) and Landorus (Abundant Shrine). Note : You must have caught Tornadus from Pokemon Black and Thundurus from Pokemon White in order to get Landorus afterwards.
it is your choice since both has different things: Exclusives to Black Legendaries: Reshiram: Dragon/Fire, Tornadus Flying Black City Opelucid Gym leader is Drayden (male pokemon) Exclusives to White Legendaries: Zekrom Dragon/Electric, Thundorus Electric/Flying White forest Opelucid Gym leader is Iris (female pokemon)