If you would like to have a unique theme to impress your guests add a Spanish theme for a unique and slightly sophisticated event. A Spanish theme is a very good option that you can consider for your event. It is elegant, refined but enjoyable nature.
Also, a flamenco performance would add the perfect touch to your event. You have several options, a performance with dancers, musicians and singers or just 1 or 2 guitarists for background music as well as a small performance with 1 guitarist and 1 dancer.