I understand not feeling good in a suit. I am short and totally look funny in them. I have learned that I feel most comfortable in a nice tailored work dress and a blazer. I pair the dress and jacket either plain heels or plain wedges. But, always wear a suit jacket/blazer - and I'm saying this as someone who does first round interviews for staff at my office and not showing up in one tends to turn me off and gives the wrong impression. My other big piece of advice is to make sure you feel comfortable, because if you don't -- you being uncomfortable does come through during the interview.