I don't have the answer you are looking for but I would say that if you are planning on cranking knobs for the different distances you will be shooting then the scope height becomes less important than many gun publications make it out to be. (Sounds like you have a Niteforce scope project.)
Having the scope mounted close to the bore helps a little bit when zeroing the scope for a "point blank range". It will increase the durration of coincidence of the arcing bullet path and the straight line of sight for a slightly longer distance but not enough to worry about.
I'm not telling you to abandon your goal. I just hope to put you at ease if you don't find just the right mount to clear the barrel by the thickness of 'squito wings. /ubbthreads/images/graemlins/laugh.gif