In Spain, it is generally best to hide your Spanish background as with the youth unemployment level there schools get literally thousands of CVs from Spanish looking for work as English teachers, and the wrong name can find a CV quickly in the bin if a DoS is busy!
July is a bit late, but not impossible. Some schools will need extra teachers or find that their teachers don't turn up in early to mid October, so if you can fly out instantly there are some options. Better, though, to get qualified by July and get some job experience in a summer school in the UK while you apply for jobs in Spain
I worked there for two years in 2000-2002, so some of that might be different if the market for teachers is (even) more competitive now. Anyone else know?