I'm going to post up the loadouts I'm using for Alpha server as I go. Just to get started I'll copy the Squad Leader loadout for co12_Cut_The_Mustard_v1.

I was happy to finally find out how to add stuff to the backpacks since all the tips I could find leave the sytnax out. What a trial by error process for something so simple.

us_sl.sqf
//Squad Leader Loadout

private ["_unit"];
_unit = _this select 0;

removeAllWeapons _unit;
removeBackPack _unit;
//_unit addMagazine "30Rnd_556x45_Stanag";
_unit addweapon "SCAR_L_STD_EGLM_TWS";
_unit addWeapon "M9SD";
_unit addMagazine "15Rnd_9x19_M9SD";
_unit addMagazine "15Rnd_9x19_M9SD";
_unit addMagazine "30Rnd_556x45_Stanag";
_unit addMagazine "30Rnd_556x45_Stanag";
_unit addMagazine "30Rnd_556x45_Stanag";
_unit addMagazine "30Rnd_556x45_Stanag";
_unit addMagazine "30Rnd_556x45_Stanag";
_unit addMagazine "30Rnd_556x45_Stanag";
_unit addMagazine "30Rnd_556x45_Stanag";
_unit addMagazine "HandGrenade_West";
_unit addMagazine "HandGrenade_West";
_unit addMagazine "SmokeShell";
_unit addMagazine "SmokeShellGreen";
_unit addMagazine "1Rnd_Smoke_M203";
_unit addMagazine "1Rnd_SmokeGreen_M203";
_unit addMagazine "1Rnd_HE_M203";
_unit addMagazine "1Rnd_HE_M203";
_unit addMagazine "1Rnd_HE_M203";
_unit addMagazine "1Rnd_HE_M203";
_unit addWeapon "NVGoggles";
_unit addWeapon "Binocular_Vector";
_unit addMagazine "IR_Strobe_Marker";

//BACKPACK
_unit addBackpack "US_Assault_Pack_EP1";
clearMagazineCargo (unitBackpack _unit);
(unitBackpack _unit) addMagazineCargoGlobal ["30Rnd_556x45_Stanag",4];
(unitBackpack _unit) addMagazineCargoGlobal ["FlareWhite_M203",4];