Rapper turned sports agent Jay-Z is “thisclose” to signing Oklahoma City Thunder star Kevin Durant to his Roc Nation Sports banner, sources say. The Durant deal will come on the heels of Hova getting his license to be an NBA and MLB agent. Jay’s dumping his share of the Nets to land NBA clients, since team owners cannot rep players, under league rules. On Wednesday night, the rapper put on his music mogul hat and came out to support his Roc Nation protégé J. Cole at the “Who Dat” rapper’s free Irving Plaza concert. Fans were let in on a first-come, first-served basis, and many brought $1 bills for Cole to autograph as a riff on his hit “Dollar and a Dream.” We’re told Jay-Z sat in a balcony booth during the show and sipped D’Usse cocktails, then stayed late for a surprise second set after 11 p.m. that Cole put on for those in the crowd, some of whom had waited on line since 2 p.m. Drake also popped in to perform with Cole, which got Jay standing and raising a glass during the Canadian rapper’s rhymes.