The big_boy.zip file you have requested: Modifications / Unit Mods and Unit Packs / Experimental Mobile Weapons Platform (1.0) - 2.35mb is not available. Perhaps try browsing all files for the game Supreme Commander: Forged Alliance and upload any files you want to share or are missing. This is the only information we could locate:
This adds the Mobile Weaponsplatform unit to the game.In fact it is a Fatboy without the ability to produce units. This is done so the unit won't be overpowered.The new unit has a longer building time and wil cost more then the orinal Fatboy The Big Boy is a version of the Fat boy with a bit more firepower but without the ability to produce units or to refuel air units.