I think you're close on nailing it, if not already so. Like the jumpsuit and jacket. In the end, at these types of events, people check you out from the chest up, because you're probably sitting behind a table (at a bar), or standing in semi-darkness (club).
Have you taken the likely weather conditions into consideration with your choice of style/fabrics?
I would ditch the shoes and get something solid but glam that you can walk/dance in. And I don't mean sparkly Fitflops! :-) Maybe get some cheap pumps and shove them in your bag. Or this folding ones by butterfly or whoever.
Have you got your makeup and jewellery sorted? And hair? A basic outfit 'dressed' right could be the clincher. Good underwear too?
Can you ask one of the youngsters if you are on the right track? After all there are all kinds of clubs, but I guess you're going to something mainstream with a glam dress code. But, reckon you've got it pretty sussed. Get the outfit sorted and concentrate on getting trashed having fun. Can I come too?