Municipal Wireless Hotspot

Hi
Our Local Municipality is investigating the following and I am hoping someone can provide ideas/advice:

We would like to provide free basic internet in some of our more disadvantaged areas. The most cost effective way would be by wireless.
The idea is to basically have an open hotspot but limit each connection to about 64k or less (kind of like a fast dial-up). I also want to limit usage to a more “work related” type and block P2P, Torrents and such. Basically strip it down to http, https, and email. Perhaps even block a few inappropriate sites. I also don’t want clients to be able to see each other.
I was thinking of installing an Uncapped ADSL line at a highsite with a few 90 or 120 deg sectors and then putting a few omni’s with F20 Pro card on lamp poles throughout the area operating in a type of mesh.

Has anyone done something like this before?
Is it possible?
Would I beable to get away with just Mikrotik boards, or would I need to put a computer in somewhere?