What would be best for my problem? Significant midface deficiency (Photos)

Based on your photos it appears that cheek augmentation with implants, possibly addition of fat grafts is your best option. Silicone implants are used most frequently for this purpose. You should consult an experienced board certified plastic surgeon with good reputation in facial implants to discuss your options. Good luck.

Facial symmetry and volume of the cheeks can be created with well-placed fillers (Voluma, Radiesse, Bellafill) and Sculptra. This would let you try on the look before committing to a permanent option. Implants or fat are alternatives. Implants can be customized to desired results. With fat transfer, harvesting is important for successful fat transfer. I use gentle water-assisted harvesting to get the most viable fat to transfer. I combine with prp and sculptra to improve results. I recommend getting a formal evaluation with a cosmetic dermatologist. Best, Dr. Emer

You may eventually decide to have an implant but that is surgery. Why not see what the area would look like with cheek filler such as Voluma first?

Silicone (solid) implants will give you what you want if done by a very experienced surgeon. These come in many sizes which should be chosen by you and your surgeon. This is a permanent solution and does not have the variability of fat. 

Submalar seems like a logical move.  You should also explore mid-face implants and/or fat transfer.  Silicon would be my choice of material.  I'd start with Dr. William Binder, Dr. Jonathan Sykes, or Drs. David Lieberman and Sachin Parikh.Chase Lay MD