Image locating devices are commonly used by astronomers to help them locate celestial objects with their telescopes. These are called finderscopes. They come in many different varieties. If you visit any website that sells telescopes they will have an assortment of finderscopes. I have a TeleVue telescope and use their Qwik-Point finder that looks like a rifle scope. This is a non-magnifying type of finderscope. As you look through the finderscope it projects a red dot that you place on the "target". It will also work on birds in daylight hours. It is made to fit the rotating collar on most refractor telescopes and will probably not fit on a spotting scope. Try these astronomy dealer websites and perform a search on "finderscopes".
http://www.astronomics.com
http://www.buytelescopes.com
This will at least give you a good idea of what these finderscopes are.
Carl