Am I a good candidate for a jaw augmentation and or gonial modification? (Photo)

Your face is very interesting because you have a nice profile, but you look a bit "bloated" from the front (right next to your mouth), and I believe that is why you see disharmony in your face.
I don't believe you have considered having custom cheek implants to lift your mid-face. Notice the depression right under your eyes next to your nose. Removing some of the buccal fat pads and having cheek (zygomatic) implants will make you more chiseled and harmonious.
The baby fat or "chubbiness" in your lower mid-third produces a disbalance. Your mid-face would benefit if the upper section were broader than the area next to your mouth.
Your jaw angle isn't narrow but high, and perhaps vertical lengthening jaw implants will give you a more defined jawline. However, we would have to do some experiments before I can suggest anything with certainty.
My team and I can help you see the best solution for your aesthetic goals. Good luck.