I am looking for tools for Ubuntu that can be used to EDIT ISO Images. Including ISO images that are bootable like Ubuntu and Windows ISOs. Not only edit but save the edited ISO and can still boot when burned on an USB Drive or CD/DVD.
I have used ISO Master to add files to ISOs before. It is suitable for what you require because it retains the state of whether or not the ISO is bootable. I have used it in the past to add other content (like music) to a live disk. Note, however, that after making changes to an ISO file, you can only "Save As", i.e. another ISO file will be created, so make sure you have enough disk space for both.