Is the Basque Museum worth a stop? I read that the signage is in Euskara and French - with a guidebook in Engilsh available. Are there English-speaking guides available?
you can contact them and ask them
http://www.museebasque.com/fr/contact
It's been quite a while since we were there, but we enjoyed it. I don't recall any problem with signage.
Info in French and Spanish indicates that they normally only have two tour times on the first Sunday of each month. I'm guessing that these are not in English.