well to be honest i only fought 3 bosses from the colorful magic mod, I really dont go out of my way to find them, I ony found those three by chance two of them were Unbra (wrong spelling?) and Jack The Ripper, those were not really hard but the first one i fought was really cool and he isn't in your list, it's called Bahamut and i found him at labyrinthium (again, wrong spelling?), that one was a lot better for me,if you want to fight him head on I advise you to have the "Regenerate" spell on hand, well sorry if that was too long, just wanted to share my experience with you sooo hope you have fun mate