Current recommendations for a new roof?

I am looking for current recommendations for or against a roof installer. 
I very likely, almost certainly will be having a new roof put on an Eichler and  I am currently focusing more on who will do the work as opposed to the type of roof although input on either will be appreciated.  Since companies change over time with companies coming and going and with new roof technologies being brought to market with other roof technologies disappearing, I hope that asking this question again is relevant.  Of course, the home is an Eichler with flat and low sloped roof sections. In line with this forum's ground rules, please PM directly with recommendations pro and con.
Thanks
Ken