You can use all, any combination or none of these addons to play the mission:

PG Services - Private Military Company:
http://forums.bistudio.com/showthread.php?159271-PG-Services-Private-Military-Company

Adds more clothes for armed civilians, also you can ask PMC-team as Land Support (more expensive but with bigger team than the INF-team).

F/A-18 Super Hornet:
http://forums.bistudio.com/showthread.php?164308-F-A-18-Super-Hornet-for-ARMA-3

Adds the fighter to possible support and can be purchased from airfield for player to fly it.

NATO SF and Russian Spetsnaz WEAPONS:
http://forums.bistudio.com/showthread.php?160599-NATO-SF-and-Russian-Spetsnaz-WEAPONS-for-A3

70% of AI use weapons from this addon, player can also call crate drops with the addons weapons.

AV IndUs (US Army inspired units):
http://www.armaholic.com/page.php?id=21361

Changes player team and all US units to use these units. Not yet 100% currently added for player (only uniform).

Hidden Identity Pack:
http://www.armaholic.com/page.php?id=21614

Adds more masks for armed civilians.

AiA-mod:
http://forums.bistudio.com/showthread.php?152706-All-in-Arma-(AiA)-TKOH-OA-A2-A1-merge-with-A3

Adds A2/Operation Arrowhead soundtrack.

You can also use the weapon addons listed in Whole Lotta Stratis-mission page, but these are not yet fully tested. There could be some non-existing classes that break ability to load savedgames. Please report if you spot missing class messages.