I can't battle using 4th Gen games because they don't support secure wifi.
If you have a BW or BW2 cartridge, but just not pokemon, I can pokesav (artifically create) some pokemon for you and trade them to you.
Or there are emulators (pokemon showdown, Pokemon online) where you can battle online. I don't like them because it takes people away from Smogon, it is so impresonal, and I have a hard time following the game with thegraphics.