Your best bet is a specialist currency broker. They usually charge a premium of about 1% of the interbank rate (banks generally have a mark up of about 3%). Some of them will also do the wire transfer for free.
You should get quotes from several, since they have slightly different offers. Just google currency broker and ask a few for a price.
You should get quotes from several, since they have slightly different offers. Just google currency broker and ask a few for a price.