Did you try the takeweapon function?
self takeWeapon("killstreak_name");
Not sure..Code:killstreak_uav_mp killstreak_helicopter_mp killstreak_ac130_mp killstreak_predator_missile_mp killstreak_helicopter_minigun_mp killstreak_nuke_mp killstreak_precision_airstrike_mp killstreak_counter_uav_mp killstreak_sentry_mp killstreak_helicopter_flares_mp killstreak_emp_mp killstreak_stealth_airstrike_mp killstreak_harrier_airstrike_mp