C.S.
I would recommend the bark collar, they aren't too expensive, around $30 and they aren't painful for the dog. It just has a box on a collar that sits on their voicebox, when they bark it sends a high pitch sound or some of them give a little shock.
We use a actual shock collar on our dog b/c she had major behavior issues and we saw a great improvement in just a few days. Now even without the collar on she hardly barks at anything and at most it is a bark or two not a complete barking fit like before.
good luck