The only tools required when i did mine was a hacksaw and a vice. Ihad an old projection eyepiece adapter that got sacrifised for the project but if you have to buy a finder plus an adapter your most probably better off just getting a Stellavue 50mm finder as they are setup to use removable eyepieces ect just like a main scope.There is an adapter available to use the finder as a guide scope as well.
http://www.stellarvue.com/f50.html
Mark
