Live in Athens and commute to Huntsville is my advice. Rent would be cheaper and the commute isn’t bad depending on which part of huntsville he’s going to be working in. Also as others stated avoid north huntsville and anything east of research park. Madison city limits is going to be expensive however just outside the any of the city limits would be the places I would recommend. Send me a message if you would like more particular details.
This is exactly what I was going to tell you! Athens would be my area of choice, but the housing allowances are going to really be expensive. There are businesses popping up everywhere, as well as housing! My wife is a realtor in the Shoals area, and if you need to know more, ask Bar7mag aka Clint Vandiver on here for advice. He is a realtor in the areas you are asking about and used to be an aldeer sponsor on here.