I am going to speak from experience here. I love my trek 520. I am 6'3" 215 (been up to 235 while owning the bike, eek) and it has seen me through all sorts of activity. I've put an average of 3 or 4,000 miles on it a year since I've owned it and couldn't be happier. I commute on it, and have done some loaded touring (not as much as I would like) and century rides.
Maintenance has been a breeze. After the initial break-in phase, I've rarely had to true or re-tension the wheels. I am hard on pads and will probably need new rims before too long.
So what I'm trying to say is possibly a used, steel touring bike could serve you well. You could put any sort of handlebar you want on it, and it has all the braze ons and eyelets for racks, fenders, etc.