In Celadon's tallest building.
You can find it in Pokemon Platinum, Pokemon Crystal, Pokemon HeartGold, and Pokemon SoulSilver.
POKEMON SOULSILVER come with a poke walker and the Soulsilver game
Game Freak, same for all the handheld versions of pokémon... Hope this helps :D
You cannot battle between a Pokemon Black game and a Pokemon Soulsilver game.
you can find ds emulators and game files on coolrom.com
You cannot get it in the game, however with the pokewalker, you can find it on a route.
At the beginning of the game you can get a sentret and evolve it into Furret.
there is a game corner on Pokemon soulsilver in goldenrod city right above the Pokemon centre
Pokemon soulsilver and Pokemon heartgold are basically the same game just different versions but i do recommend buying Pokemon soulsilver
Go to a game stop event for obtaining Celibi
maybe, but i find it very unlikely.
You can trade one from another game, in soulsilver you can find a trainer with a chimchar, then go to the GTS and evolve it.