For info, I contacted several insurers or brokers, including one based in Spain (cover was no where near good enough), Intasure (comprehensive cover) and a Uk firm which specialises in holiday home insurance both here and abroad, we already have UK insurance with them - www.schofields.co.uk. Schofields and Intasure had similar comprehensive cover, including loss of income, etc. The excess was higher on Intasure and they were marginally more expensive than Schofields, so we went with Schofields.
Do note that you need more than just contents cover - the Community buildings insurance is very basic and just covers the external shell - our mortgage company insisted on buildings cover as well as contents. I get the impression this is the norm in Spain and was something that was discussed briefly at the PM2 AGM.