I would like the risk of taking the Big Man. 1st rounder big men usually seem to go either way, Really Great or Really Bad. But I still say take Thabeet, b/c his possibilities would be higher with Thib training him, and Kg working with him. Even Perkins has developed a better midrange shot from 10 feet out.
So yea, trade Rondo for Conley and pick up Thabeet