There is always a crew of three officials working an NBA game. The lead official is the crew chief. He is usually the most senior official of the three, but not always.
He isn't necessarily the official doing the toss (rule changes in years past state that the crew chief, or referee, can assign another official, one of the umpires, to toss). You can always tell the crew chief when the replay comes into play, as the crew chief makes the final decision.
There are eight crew chiefs in the first round. My eight crew chiefs are No. 15 Bennett Salvatore (pictured); No. 26 Bob Delaney (who was injured last year), No. 27 Dick Bavetta, No. 18 Mark Wunderlich, No. 17 Joe Crawford, No. 43 Dan Crawford (widely regarded as the best NBA official), No. 48 Scott Foster, and No. 14 Joe Derosa.
I wouldn't be surprised if No. 49 Tom Washington and No. 13 Monty McCutchen get crew chief assignments however. As a note, No. 29 Steve Javie has been hurt with a knee issue, and will miss playoffs this year.