Insurance questions

I am through with active treatment, but stage III so will never be without worry.  I had wanted to go to MDA for a second opinion back during treatment, but my insurance wouldn't cover it and there was no way we could afford it.   Now I'm working again, and it's our open season.  I work for the government.  I want all my ducks in a row in case I developed any further problems.  

My ONLY complaint with my current health insurance, which is a plan local to my isolated city, is that it does not cover out of this state.  There is absolutely no point going anywhere in this state for medical care other than the city I'm in, so really I'm limited to my city.    

My options are BC/BS, GEHA (Government Employees Heatlh Assoc), and a whole bunch that are through postal workers or special agents groups that we can join for about $40.  Does anybody have any experience with any of these?  Any experience with what to look for in an insurance plan, or where I might find reliable ratings?