I'd look at the Jamis Coda. It sounds like it would fit your need. Fixed gears or the Trek Soho can't help much about.

I really can't say why you are having problems shifting and problems with your drivetrain without knowing something about how you ride. You should shift gears before you need to and avoid cross chaining if possible. You should also clean and lube your drivetrain when needed. There is plenty information available on the internet.