Different Items

[Monrezz]

Okay...I'm making a quest in The Arena (I have custom mobs there) in which you have to rescue King Zaixelek. You have to get 4 bits of armour from "God_of_War", who drops about 1 or 2 different pieces of loot per kill. When you give him the 4 bits of armour, he will give you a new item and make you level 65. So far I have this:

/*  Zone:arena  ID:178204 -- King_Zaixelek */
EVENT_SAY { 
if ($1- =~ "Hail") { say("Hail $name . Please, you must rescue me from the God of War. I have been imprisoned here for over 2000 years. He has been keeping me alive...but why? Will you [rescue] me please!") }
if ($1- =~ "rescue") { say("Oh thank you thank you thank you! I must warn you. He is not like any other Gods I know of. He appears to be invincible; his health regenerates at an amazing rate and no other God has managed to get his health down noticeably. Many guilds and coordinated raids have been attempted on him. None have been sucessful! But you must please try...you don't know what it's like! I will give you a very hansom [reward] for his sucessful downfall.") }
if ($1- =~ "reward") { say("I will give you armour you have never seen before. Not normal armour but armour even the Gods themselves would like. It will protect you from anything that tries to attack you. Do NOT become careless though...only 2 mortals have ever worn this. I am one, the other...you will find out in time. Heed my advice when wearing it - be careful. I must of course have proof that he is slain however; I am no fool. Bring me 4 pieces of his armour and I shall give you one piece of mine. Return to me with this for your prize.") } 
} 
EVENT_ITEM { 
if ($item0 == "1001" && $item1 == "1002" && $item2 == "1003" && $item3 == "1004") { say("Praise you $name - I knew that you would be victorious. I reward you with this armour and pray that it will help you in your fight against the unholy forces of Norrath.")
spawnitem(1016)
level($userid,65) } 
} 
EVENT_DIE { 
say("Why...*cough*...why did you kill me...?..*cough*...") 
shout("Finally...freedom. Thank you $name . I pray you good luck in your adventuring.") 
me("King Zaixeleks spirit rises up into the air and disapears.")
level($userid,60)
}
EVENT_SPAWN {
shout("Please somebody help me! I have been imprisoned by the God of War for over 2000 years. Somebody, please rescuse me. You shall be rewarded!")
}

/*END of FILE*/

The only thing is I want you to be able to hand in any 4 items out of this list:

1001,1002,1003,1004,1005,1006,1007,1008,1009,1010, 1011,1012.

So for $item0 I want you to be able to hand in item's 1001-1012, and the same for slot 2, 3 and 4.

How would I do this, please...?