Missing 6 total of teeth on top. Am I a candidate for snap on teeth? (Photo)

Snap-On Smiles are designed to use your existing teeth as support to hold the 'snapped-on' smile in place. They typically aren't recommended to cover large gaps in the smile, such as yours. You might want to consider a dental bridge, dental implants, dentures, or dental-implant supported dentures. A consultation with a cosmetic dentist can help you explore all options based on your unique situation. It's important to replace missing teeth as soon as possible after tooth loss as it will affect the shape of your face and neighboring teeth (as you've already seen evidence of with the loss of two more teeth.)Best of luck. 

when people are missing teeth there are many choices you can make to replace them .    Denture's or partials, implants, or bridges.    You need to decide how do you want to replace you teeth. Do you want teeth that are permanent that you do not want to take out, or keep in permanent .   By looking at your photos , they did not rebuild your jaw or bone grafts the area where you lost your teeth.  As a result, the cost for implants would be more expensive. A removable partial could work but you would have to take your teeth out at night.  You may prefer to do a zirconia bridge ,   That would be cemented into your mouth and take about a week to make.   You would need a 6 tooth bridge .  Cost about 600 per tooth.