The difficulty, and the crux of the OP’s question, is what constitutes “overdoing it” with respect to dressing appropriately for this interview.
To a certain extent, it may depend upon which city or which region of the country.
P.S. @dot228 : Please update us on you interview afterwards. Also, are you willing to share the city or region of the US ? I ask because dress standards are often quite different in the Pacific Northwest (Seattle & Portland), then for Washington DC & the Eastern Corridor.
Although long ago, and standards have changed, I was once told that I would not receive an internship offer from a major Southern law firm because I did not wear a suit (I wore a blue sportcoat, khaki pants, white shirt, tie & dress shoes–all brand new. The partner who told me that did so as a favor. And this was the case even though my dress was common in their office–just not for interviews, meeting clients or court appearances.) Also, I often informed of hiring discussions between HR & my relatives who interview.)