Shackles aren't tall enough to require brake line or shock changes.
If your bushings look shot, then installed a new set on the shackle end of the spring makes sense. Broken down rubber bushings can lead to sloppy handling charateristics with taller shackles.
The only thing that will change with your ride is the castor up front. This will cause a loose or wandering feeling on the highway (not noticeable at lower speeds). For many folks this does not bother them. If it bothers you, you can easily install some castor shims to correct things and make your handling feel tight again.