Some problems with the tracker has been solved, and I am now able to log time and coordinates in a database. Following the amended design:
Using CloudFront to redirect the non-SSL traffic didn’t work so I manually setup my server to accept non-SSL traffic on specific paths and redirect any other traffic to HTTPS.
A quick test with a API (written in PHP) has been successful, and the GPS data and timestamp has been recorded into the database (MySQL).
The GPRS connection still unstable and I am not 100% satisfied by the library (SFRobot_SIM808) and most likely I will create my own one using the AT commands.