Long distances

Question to anyone who has a single practice or theoretical proof.

My situation is the following.

I have several : Cisco Wireless AP 1231G

I want : to make a bridge (point to point) connection on a long distance (from 10-30 kilometers).

Please point what else do I need exactly ?

High gain directional antenna, exactly from which vendor and with what gain (dBi) ?

Which antenna vendor is best for that ?

What type of cable do I need and also the vendor name ?

If you know, and you know that it works stabile, please give hand of assistance.



Thank you