Hello,
You have a quite impressing project here and I would like to take the challenge to deliver such a system within 2 months, including proper testing.
I am a web developer with expertise in PHP, MySQL, PostgresSQL, HTML, Javascript but I am also skilled in Linux administration. I have the abilities to develop a integrated solution (from a central server setup to client endpoint) to match your requirements.
On complex projects such as this one I partner with a local company here and we could ensure maintenance and further development after the application is deployed, contract based.
My technical proposal:
1. Central database on the main server: a Linux machine, running PostgreSQL server. Since it will handle a lot of connections and probably a huge database I recommend PostgreSQL over MySQL, MariaDB or other database servers since I noticed from working experience that PostgreSQL deals better in such conditions (less memory footprint, less CPU usage).
2. Endpoint HTML interface for MACs - a very minimalistic html web interface that should keep Internet traffic at a minimum level but yet easy to use.
3. Restful API to give endpoint access to MACs. An API endpoint using JSON format for data exchange should perform well on the slowest connection since data transfer would be at its minimum.
Well, this is roughly my proposal for this project, based on what I read in your attached file but I'd be very happy to get into details and elaborate it further.
Regards,
Calin Rusu.