I must have missed this but what telescope are you putting this finder on? The weight of the bigger finders matters more on small scopes (12" or smaller I mean) Also no-one has asked why do you want or need a finder now days? When I built my 16" Binocular telescope I realized there was no sensible place to put a finder. So I only have a telrad, it only ever gets used twice to help me get the two alignment stars in the eyepiece so i can align my ArgoNavis digital setting circles. I then spend the evening actually looking for long periods at objects rather than wasting observing time star hopping.
Finders are irrelevant forget them :-)
