What to wear to a post-interview meeting?

So I had an interview last week with an accounting firm for an accounting staff position. I wore my business suit (black pants and matching blazer) since it was their first impression of me and a professional interview.

They called me and want to offer me the position. They asked me to come in this week to go over the paperwork, sign everything, and meet with different people to talk about the next steps, salary, etc. This is obviously still a pretty formal meeting and I want to uphold my professional image that I gave them at the interview. I am wondering what I should wear?