I would try http://www.idealista.com/en/ or http://www.fotocasa.es/en/. They are the two biggest portals in Spain, and probably have the largest selection of properties listed in the places you mention. However, I have no idea what the agents that list with them are like. It’s a bit hit and miss I’m afraid.
If you want to try a Spanish property portal in English then http://www.thinkspain.com/spanishproperty/