Just a little more specific dress suggestions:
Go with a single-breasted, two-button navy suit. Unobtrusive pinstripes will work. Navy evokes trustworthiness and order. Three-buttons suggest trendiness. Do not wear a blazer.
White pinpoint oxford dress shirt, button-down, tab, or spread. Don’t get fancy with patterns, blended fabrics don’t wrinkle as much. No collar-bars. Have it professionally pressed before wearing.
White t-shirt underneath. Not a wife-beater.
Maroon tie, single color/pattern. No paisley. Red ties evoke a presidential image, think Reagan/Bush. You want them talking about you, not your flashy tie.
Black belt.
Wear shoes with laces, slip-ons evoke leisure. Match your shoes to your belt.
Match your socks to your shoes.
The image you are creating is not one of impressive fashion taste; but rather, one of solid dependability.
When you enter the room, greet them with a smile and a handshake. Take a cue from Bill Clinton; maintain eye-contact and smile while you are introducing yourself. Maintain eye contact until you have moved to the next person, if there are several interviewers.
While introducing yourself, enunciate your name, and smile while saying it.
Their first impression of you is the most important, and you must make sure that they remember your name.
Most important: Practice doing these things with your spouse, and ask for honest critique. Do it till you can pull it off naturally, then take her out to dinner. She deserves it after all that.
sorry this post was so long. We’re all rooting for you. Go get ‘em!