Welcome, Kwhman. Don't scoff at 5.4 miles. That's still longer than some people's rides. What matters is that you ride.

You say your LBS might not be able to get the Trek 7500, but if not you'll get a Gary Fischer? Why wouldn't they be able to get it? If that's the bike you want, then find another bike shop. I'm not saying your LBS is bad, but get the bike you want. Your location says you live in Atlanta, so I'm sure there are plenty of other bike shops where you could get the Trek 7500.

Good luck and keep on riding!! I like that you set that century goal.....keep working toward it.