After I retired recently, my wife and I decided to live for one year in Spain with our son. . We applied and he was accepted to an American school in Madrid.  We are not sure about what kind of Visa to apply for, i.e. what would make the sense,  and we have received conflicting advice. 

Typical suggestions have included
- Go on a 90-day tourist Visa. Stay for the year but don’t travel out of Spain.  OK, how risky is that?
- Try to get a ‘retirement’ visa. Try to get a ‘investment’ visa. ‘Try to get a ‘non-lucrative’ Visa.  Choices are nice,  but I’m not clear at all on why there has to be 3. We have sufficient savings for the non-lucrative visa .  Any suggestions on which to pursue. 

The Spanish consulate in San Francisco where we live does not give out much in the way of advice, so any pointers would be helpful.