Also, the lack of room in the existing main panel is another reason I was thinking about putting that sub panel in the attic. All I would have to do at first is install one new double pole breaker in the main. Would make the wife quite a bit happier if I wouldn't have to shut off the juice for as long that way.
I am slowly being convinced that the sub panel isn't needed, but it certainly would complicate things as far as keeping power available while I run the circuits. With a sub panel I could just get it all ready to go and then flip on the 60 amp breaker. Done.