Well I fractured my clavicle in 2003, and had the same problem, non-union for over 6 months, so they decided to perform surgery. Well now in 2007 I have full blown arthritis, and possibly neuropathy. There is a lot pain still and the arthritis meds dont help. I'm not one for taking narcotics so I have just had to learn how to cope. Day to day the pain is manageable, every two weeks or so it gets really bad. I tried talking to doctors but they are not much help. I'm considered an otherwise healthy 24 yr old so they pretty much ignore me.
As far as a plate. It did work for me, in terms of having the fracture heal. But you will have to take it really easy for a year, maybe more as it was in my case. Plates do have a high incidence of breaking too so be prepared for that.
Wish you the best.