Hi there. Are you going to be living in Spain. If so you can just get one from a Spanish mortgage provider. If you do that they’ll have to be listed as authorised to operate in Spain with the Bank of Spain.
You can find out about whole buying process here if you need more information. They also highlight that for a rural property you will only ever be able to get a mortgage for 50% of the bank’s valuation of the property. Something that never occurred to me.