Based on your options, you probably know that when holding this item, only one move can be used. Therefore, your starting move must be very good.
Looking at your moves, I'd say quick attack is pretty much useless. If your using quick attack as your main move, a choice scarf is useless.
Close combat would need the choice band since close combat reduces your defense and special defense after every move (and Staraptor isn't very strong in these stats). With this, you can boost your attack to knock out your opponents before they knock out you. Plus, being your only move, you're looking at a fast death with your defences constantly decreasing. Intimidate will work great with this move.
Brave Bird would definitely be optional on which item you will use, but is basically pointless if your ability is intimidate. Using this move is much more suitable with reckless as the ability.
U-turn is not a bad move because it can deal damage early, and you can switch out to a better match-up for the opponent. U-turn will work great with the choice scarf as you will need the extra speed.
Overall, I think with this Staraptor, you should try to give it return - along with maxing out its happiness. Therefore, you have STAB, high attack, and your choice of item is completely optional (no bad ones - but I'd choose choice scarf). If you are willing to change staraptors, use a reckless staraptor with brave bird (holding a choice band - although it doesn't matter).
Your choice! Hope I helped! :)
