Thanks for all of your advice.
The 2008 Trek 520 with MTB gears arrived home today (from the local Surly dealer). So far it seems like a great bike. It fits well and was out on the roads this afternoon.
Since I am a woman, heel strike shouldn't be a problem.
How ironic; I was flat out told by the local Trek store that the 520 is not even made in my size (43/45 cm). They recommended the Specialized Tri-Cross or a Cannondale instead, neither of which fit me. The local Surly store didn't have any LHT's in my size to try out, but they did have the 2008 Trek 520 and were willing to order a LHT if I wanted it instead.