wifi project

We have a wifi project to cover a total area of 10kmx10km (within a city, considering a plane area) with few high constructions. Please could you help me with this project?
Below some more information:
We need a quote and your suggestions to implement the project described below .
WiFi network requirements
a.1) Basic area 3kmx3km (to begin)
a.2) Total covered area 10km x 10km (aim) B) 2.4ghz WiFi technology
C) This internet service must be provide only for VoIP in WiFI telephones, personal computers with internal or external usb WiFi device.
D) In the aim area 10km x 10km, we expect to have at the begining 500 users simultaneously connected.
E) Upload and Download flow, will be only from VoIP use.
F) We also need 400 wifi phones, 500 wifi usb 2.4ghz adapters and other equipment to work on this network.
We need to know your options and prices to fulfil this requirements.
Thank you
Marcos Antonio
info@gruposolidez.com

wireless device outodoor wifi