Yes, take your pick from
ArmA 2 or
Operation Arrowhead. You would need to use
CAA1 which should include sahrani. You need to put the mission in your MPMissions folder inside the ArmA 2 directory.
To play in LAN obviously all your friends have to be on the same network, simply select LAN mode in mp lobby and create a game, select the sahrani map then the mission, and your good to go.