Here are some references from mil-rad.com to use to determine what scope ring height to use:
All links used with permission of the mil-rad.com site owner.

Here is a Scope Ring Height and Clearance Calculator.

If you are using a rail that is not a 0 MOA rail, you will want to know how much that will affect the height or the objective bell this Scope Mount Cant Offset Calculator.

In addition, Here is a list of some scopes and their outer tube, objective bell, and ocular bell outside diameters, as well as diameters and heights of Badger, Seekins and Spuhr tactical rings.



From the Burris Optics website, here is a list of Burris Signature Zee Ring heights (Note that the burris measurements are to the bottom of the inner ring, and the mil-rad.com measurements are to the center of the ring)