Everywhere in the N hemisphere that's known for windsurfing/kiting will be good that time of year. Spanish-speaking places...
Start at Tarifa or Cabarete. If they're too crowded/developed for your taste you can easily move on.

Cabarete has warmer water and a nearby surf break. If you stay at Ali's surf camp there's a language school across the road. There are heaps of holiday homes you can rent, since the Dominican Republic permits foreigners to own real estate.