Actually, you can if it has a pre-evolution form you have seen. if it has a pre-evolution form you have seen, trade for that then evolve it. i suggest going to http://www.serebii.net/chat-wifi.shtml and asking for the pokemon. you will need to use w-fi and know your freind code while trading though.
Chat with our AI personalities
You can't check what Pokemon are up for trade beforehand.
the global trade station
You can't it's impossible
It's cool.
Go to the GTS in Jublife City.