Public healthcare is usually very good but you might be limited to using your EHIC - if they will accept it- for emergencies only. Only those working here or state uk pensioners can get free healthcare, and if you are signed on the spanish system you are not allowed to use the UK one, although this may change. Private healthcare may be an option but they may not cover pre existing conditions. Check out the threads on the forum there is lots of information and probably people who have done what you are thinking of. Check out the tax implications as well you don't want to be here more than 182 days in any calendar year.