How about this dress? It is ultra cool and unique, you'll definitely stand out! In fact why not look at the brand
London
You can wear a studded leather jacket with black fitted silk dress or black skater dress with some pantyhose and buckled booties. Just a suggestion :)
You can wear any sleeveless top with good fitting to your body with jeans or skirt. If slight cleavage is seeing, do not worry for that. It is normal but you must have decent. Enjoy the party.
You can wear a sleeveless tops with jeans, Don't wear anything which you feel uncomfortable otherwise you can't enjoy there.