Hi Ed,
I was going to point you to Dan Grays web site but Mark beat me to it. To me the inclined eyepiece axis 2 mirror concept is probably preferable to the 3 mirror concept due to simplicity, although I assume you can get a much lower EP height with the 3 mirror option.
I have to say, I rather like Dan's 28" scope design (I know I am biased
, but even ignoring it has a string truss).
Cheers,