I would recommend a Jamis Coda - any year if used, but even brand new I think you're around your budget of $800. Here is why I make this recommendation...
- steel frame is smooooooth
- they have braze-ons every where for rear and front racks, pump, water bottle, fenders, etc. etc.
- disc brakes on a bike under $1k, got to love that
- insanely affordable.