I can't comment on the Trek hybrid, but it sounds like a good fit for the type of riding you described. If I were starting over, I think I would buy used and ride it for at least a year before I invest in a new bike. I don't know where you are, but around here you can always find Treks on Craig's List. There's a 2009 7.3 for $450 out there right now. http://washingtondc.craigslist.org/d...316748058.html

You're right not to worry about the saddle. You'll probably buy a new one anyway. As far as tires go, you'll probably want at least 32mm wide especially if the tow path is gravel. My only other advice would be to make sure the bike can accommodate a rack and fenders for commuting.