About the only thing in common print that I know of is a page in the #3 (new) ATM book by Ingalls (get all three if you don't have them).
Basically, there needs to be a occulting disk at the focus of the primary that blocks out the sun's image and you might as well put a window at 45deg. so that you can do some autoguiding on the sun's image when it goes off of the proper alignment. It's very important that you don't get the sun to shine past the occulting disk or the light level goes way up in the EP and quickly gets to the point where you shouldn't look at it.
You need to accurately know the diameter of the sun so that you can make the disk which is more of a cone to dissapate the light from the sun. You may also reflect the light to the side and get rid of the heat there outside of the light beam.