look into Mesh WiFi https://seattlemesh.net/
uses CJDNS for secure, decentralized mesh networking
CJDNS is a networking suite for meshnets that allows us to connect together securely by encrypting every connection from end to end, while at the same time being completely decentralized . CJDNS operates at layer 2 locally, and it can peer with other distant meshnets via a UDP interface on layer 3.
https://github.com/cjdelisle/cjdns
then look into Pro WiFI gear 31+ mile wifi links (if you get it higher on a hill it will go beyond +100 miles - http://en.wikipedia.org/wiki/Radio_horizon however with mesh networks in close proximity with each other ie every building on a street or in every car hills are not a problem)
Ubiquiti RD-5G30 AirMax RocketDish Outdoor 5GHz 30dBi Duplex Dish Antenna http://www.broadbandbuyer.co.uk/products/17003-ubiquiti-rd-5g30/
and building to building links
even 120° Secter Antena MaxLink Sector Antenna MIMO 19-21dBi 5GHz 60-120 degrees http://linitx.com/product/maxlink-sector-antenna-mimo-1921dbi-5ghz-60120-degrees/13710
3x of them give you 360° covarge and with 3x sectors you can support 450 Simutanus wifi users (150 per sector with a pro wifi card) Pro routers + Pro Wifi Cards
MikroTik RouterBoard 493AH
http://linitx.com/product/mikrotik-routerboard-493ah-with-routeros-level-5/12258
3x
MikroTik R52Hn 802.11 a/b/g/n High Power MiniPCI Card http://linitx.com/product/mikrotik-r52hn-80211-abgn-high-power-minipci-card/12801
you could get 2 Watt (2000 mW) WiFi bootsers
WiFi Mesh would be much better http://en.wikipedia.org/wiki/Wireless_mesh_network Self Repair
Self Seraching
Redundancy & Security grows the bigger it gets Small Running costs