I am probably over simplifying it, but the default insert/edit link
option that is also available in the WYSIWYG editor seems like the perfect solution. It would be great to use this because clients are already familiar with this interface (see screenshot).
If I want to wrap this in a button I have to give them a different UI to accomplice the same thing. First a checkbox do you want a button? Next do you want a external or internal button? Than the button title, button url and if it should open in a new tab or not, all this is all caught in the simple interface that WordPress is already providing.
