Your best bet is to go to real estate networking events near those areas and talk to those who have invested in those areas.Best of luck!

Is one a clear choice and I am having trouble seeing it?

You're best bet is to call a few brokers local to the area and see what they can come up with.It's definitely going to be a surplus or excess carrier that will do it and the premiums will be high. 

You better reach out to them days before the auction and give them a simple choice: allow foreclosure sale  to occur or allow you to take it over from them, with equity justifying your purchase.    

In my opinion, that is a riskier bet because you have to have a big pile of cash for contingencies.  

I haven't seen any statistics to this effect and I don't think any has necessarily been compiled but I bet I wouldn't exaggerate if I state that 95% of the value of real estate in Southern Spain or at least the province of Andalucia is in the Costa del Sol.

$280k home for $2,500 rent is a personal choice.

DSCR is going to be your best bet here.

Then your best bet are probably community banks which have more flexibility (albeit worse terms) than larger banks and also worth looking into are DSCR lenders.

I am sure there are other good choices out there, but strongly recommend them.Stessa is lacking tenant communications and maintenance tracking, but overall stands up pretty well as free, or nearly free.Buildium is pricey and has a learning curve, but if you are going to exceed 20 units, definitely look to migrating to a real professional package like buildium