Well, if you plan to leave the Litey in, then you are going to need the double. This means that the cable you want is the one that plugs into the motherboard and has two more plugs for the burners. One is for the master and the other is for the slave. Make sure that which ever burner is going to be the master, you set the pins for master and the other to slave. These are found at the back of the each burner.
Just get two sets that are doubles. Connect both cables to the IDE connectors on the motherboard (the end that has the single plug) then at the other end you'll have two plugs where you will connect each burner. If you connect two burners on one cable, then follow the steps above. Then connect the third burner to other cable. You'll have one plug unused on this cable. Make sure that the one by itself is set to master. Just choose which two you are going to connect together and the third will be by itself.
Hope this helps.
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