Palms in your Spanish garden looks excellent, gives a nice atmosphere of tropical surroundings and attract a variety of interesting wildlife feeding of the dates. If you dont have a Spanish garden already equipped with palms if its possible to buy them in all sizes in most bigger garden centers at relatively affordable prices.
Be careful when buying though, you need to buy palms that will thrive in the specific location of your garden where you plan to put them. Some palms need plenty of direct sun, others prefer a bit of shade. Some palms are happy to grow in sandy earth, others need a more rich mix. Ask a skilled gardener before committing to a big purchase of palms for your garden.