Keep in mind that TSA will wash you out if you don't meet standards. Training is difficult for some, easy for others. My class had 24 people, one busted the oral, four busted the sim. All were retrained and passed.

Hours are nice (don't flame me), but buzzing around in a 172 will only help you for the first couple of hundred hours as a CFI. Going into ORD will be much more worthwhile in my opinion.