It depends on what your goals is.
Are you going to keep the HD and just install an SSD side by side ?
or are you removing the HD and replacing it with a new SSD ?
If its the later, copy all the installers from Command center and paste them back in when you install the new SSD. This will avoid having to re download everything all over again.
Because Sonar is now on your main hard drive than yes, you want to uninstall it and personally, I would wipe the drive clean/reformat but make sure to back up everything first (projects, files, exc).