80211gn setup

Hi guys
I need to setup an 802.11g point to point link on 11n to provide higher bandwidth.
what will I need?

Actually, distance is not an issue < 3km but I want it on 11g to escape interference to some degree and take advantage of the 11n higher bandwidth.

GO AHEAD WITH IT AND IF U AVE ANY PROBLEMS THEN TELL US THE PROBLEM AREAS