This is sounding a bit self-inflicted, especially if someone from ISU reads this board. If your son wants to play at the school, it will never happen if he never talks to the coaches. I am not saying your son should call and say "remember me, the guy you didn't make an offer to in High School." I would suggest that your son ask his JC coach to make the call to sell him to the coach. If that doesn't work, JC players can also go to their prospect camp.... Maybe a heart to heart with the JC coach about his 4 year prospects wouldn't hurt either.
The "trick" is for your son to get the ISU coach to want him, you can talk all day long but until someone gets the coach to come watch your kid play the chances of any type of opportunity from the school are pretty much 0. I would not discuss the stats or comparisions to other players as the college coaches don't really care about them, (and they might think the world of the player you are comparing your son to). Coaches only care about what they see in your son's ability.
Good luck.