First, any choice is a gamble. If you think Stockton is a "sure thing" you are certainly overconfident in your ability to predict the future.
Second, read the last few chapters of Stockton's book and see if you change your opinion. He admits to his inability to lead the young players on the team as it fragmented in his last few years. It was a very honest, authentic and grounded self-reflection which rang true to me. He did a lot of reflecting on the "good old days" of the NBA. Stockton would be miserable not being able to get out of the spotlight. He is very introverted and would not be sustainably fulfilled as an NBA coach. And he knows it, so I doubt very much if he would consider an NBA HC job. I see him as an assistant or as a college HC (If Gonzaga's coach were younger, he could be stepping in).