Synchronized digital cameras
Take a look at the Raspberry Pi Camera Module...



https://www.adafruit.com/product/1367

This is a pretty mediocre module, but might be good for your project because...


It is capable of capturing a single whole frame and you can trigger that from asn external system via a pin (FREX), so you could trigger a pair of these sensors with a single signal. 
You can manually control all of the image parameters, so you set a pair of modules to capture matched images.
It is cheap, readily available, and comes on a handy breakout board.
It is documented.
You can plug it into a Raspberry Pi and have a working system to start with and then make modifications to get the functionality you want, rather than starting from scratch.


Below are some suggestions on how to start. They are in order of increasing tightness of sync, and increasing effort so I would test at each step and stop as soon as you get enough sync for your application. 


Get 2 Raspberry Pis and get them working with 2 normal, independent Camera Modules. 
Modify code so you can manually adjust image parameters, and set both sensors to use the same parameters. 
Modify code so you can enable frame exposure mode. More info in section 4.10 of the data sheet. 





Get physical access to the FREX pin on each module. 




I don't have a module here, but this could either be as easy as tapping a test point, or as hard as desoldering the module form to board to add a line. 

Connect both FREX pins together and use them to trigger a synchronized capture. 


Get Physical access to the XCLK clock input on both modules and get both modules to run form a single source. 
Write up everything you did because I think a lot of people would love to be able to do this!