To develop a proxy http requests

There is a SMS service provider (connecting over http), you need to write a layer between our services and the provider, you need to write a proxy that will perform the following tasks:
a) statistics (operators, regions, cost, etc. (with scalability))
b) tracking the SMS sender
C) the possibility to change settings for VMS (alpha name, etc.)
g) the ability to change SMS provider without rewriting a large amount of internal services

The documentation for the current implementation can be seen in the attachment to the project.

In response to the project please send approximate terms, the cost and method of construction