At work so don't have all info with me, but near Pau I would highly recommend Chateau de Projan. We stopped here with Speedmog a couple of years ago on the way back to Santander and we really enjoyed it.
The property has been imaginatively restored, the owner is an architect, and the family who manage it were very helpful - Richard & Christine Poullain. Richard does the cooking and the overall experience was so good we stopped an extra night.

The telephone number is: +33 05 62 09 46 21 and there is one entry in
TripAdvisor. You may also find this
site useful for B&B's in France.
Another essential stop imho is Bilbao for the
Guggenheim Museum. The Frank Gehry building is fantastic, and whilst the Richard Serra installation - The Matter of Time - is impressive, some of the other works presented when we have visited have not been of the same quality imho. Last time we stopped in
Miro Hotel which is almost opposite the Guggie (and has secure parking), but we have had good reports about the
Hesperia Bilbao too.
HTH