Fair Park has begun to hum with activity and Big Tex is all dressed up for his annual showing. As the State Fair of Texas kicks into high gear, Binh Tran will be up early every morning driving around the Dallas metroplex in search of coconuts. A vendor whose success at the nation’s most highly attended fair depends on preparation, Tran estimates he’ll need as many as five thousand coconuts for the duration of the 24-day event, which kicks off September 26. The stakes have become higher over his 25 years as a State Fair of Texas vendor. This year, his Coconut Quadruple—a coconut-pineapple slushie served in a young coconut, capped with a swirl of coconut soft serve, and finished with toasted coconut flakes—is a…