How to choose references for postdoc application?
I think, what really matters is the quality of the reference letter. As you mentioned that both the persons that you have chosen other than your mentor are highly active and are happy with your work, so getting a good recommendation letter from them would be very fine then getting a bad recommendation from a noble laureate.  Position really doesn't matter as long as you get a good recommendation.  Make sure that the person you have chosen as a recommender gives you really a good one.


  Does any personal account matter while considering a recommendation or a generic-looking letter does fine?


A well-written letter on an official notepad would be fine, having all the necessary details of your recommender with the phone number and email id.