Hi,
Thanks for sharing your Project requirement here at Freelancer and I will be more than happy to help you. Let me share with you my expertise.
I have been working with these types of projects for more than five years. I am an expert in Openwrt Deployments. On OpenWRT I have also done Hostspot Deployment with social logins like(facebook, google et al any of the publicly available authentication APIs, HOTSPOT portal per location/client is also very much achievable) and have worked on various setup and all the technologies (Apart from the Generic API provided by a Standard hotspot solution provider) that make Hotspots works perfectly. I have created in house controller to control openwrt access points, And that would be the most suitable hardware for this job, As it can supply all that information you are asking plus it can do all the captive portal stuff as per your requirements. I have done all the GRE, NAT, Multi WAN things on openwrt.
I have also configured openwisp to work with openwrt access points
I am very punctual with my work, money for me is secondary and client satisfaction is primary. So I don't linger on with pending work just to make money. I love technology hence I love facing new challenges and overcoming them.
I can assure you that I will be able to submit your task in time with quality work , I will be available more than 30 hours per week and able to start your project as soon as possible according to you.
Regards
Arjun Sharma