The
Confirm Loot Roll addon may be of interest. It will automatically confirm whatever kind of roll you do. You would still need to click need/greed/disenchant, or use a macro to run RollOnLoot with the appropriate values.
If you want something that will roll automatically on certain item types, you could try
PassLoot, but you would need to set it up to roll how you want.
If you want something that will unconditionally roll Need on everything, you could probably configure PassLoot to do that, but I don't think anyone here (myself included) will help you configure it, or write any code to do this for you, since this is not the kind of behavior anyone appreciates in a group.