Where Can One Go for Augmentation of the Temple or Forehead?

Placing a synthetic implant into the temple area is not a good idea. In our practice we have seen disasters such as infections with polymethacrylate and do not recommend it. Silicone implants are also not recommended for this area as they are hard, palpable, and feel like a lump underneath the skin. However, silicone implants are excellent for chin, mandible, and cheek implants. Consideration to the jaw implant or a cheek implants to widen the face might be a better alternative for you.

Given the volume you describe, I am reluctant to recommend permanent fillers as a solution to your problem. These generally work well for localized control. Silikon 1000 should be injected using the microdroplet technique and this would likely take well over a year or two to even get close to making a difference. Numerous PMMA complications have been reported from high volume injections in Central and South America so I would advise you against using this as well.
Fat injections may be an option for you. You may want to look up a surgeon named Sydney Coleman.

One would need to see your photos to determine what would be the best course of correction of the forehead and temples, etc. you describe. Permanent silicone implants custom made for you would be best.