In your semi-tropical climate, warm season perennial grasses would probably work best, such as Bahiagrass or Bermuda grass. These grasses will grow well in warmer climates with adequate rainfall and sandy soils. For further information on warm season perennial grasses, visit the links below.
Bermuda Grass: http://extension.missouri.edu/explore/agguides/crops/g04620.htm
Bahiagrass: http://msucares.com/pubs/infosheets/is0843.pdf
