This is my advice for what to wear to any white collar job interview.
Dark navy 2 button suit where the jacket fits well at the shoulders and back of the collar and has good waist suppression.
Trousers that are fairly slim and have a small amount of break. If it has belt loops, wear a simply black belt.
Dark blue or black socks with black oxfords, semi-brogues or penny loafers in descending order of preference.
White shirt where the collar fits very well. The rest is less important as you are unlikely to take you jacket off (do not in the interview, if it is a longer assessment day with group exercises etc try not to but it will be more likely that you will at some point).
Don't worry too much about cuffs as long as they are well fitted enough that they dont fall below the base of your thumb (where it meets your wrist). Only go for French cuffs if you have some nice conservative cufflinks already, or don't mind buying some.
Wear any tie that is conservative. Hint: if you have to ask "is this conservative?" the answer is probably not. Pick a blue or red that best suits your complexion.
Keep your top button fastened when you are standing, unbuttoned when seated.
Get a neat haircut at least half a week before the interview.
Go easy on the cologne. Have good breath. Smile and make good eye contact. Firm but not crushing handshake.
Read as much as you can about the company.