theo's advice I think is the best in this thread. When interviewing, just stick with as conservative as possible. Please avoid 3-button suits unless you are a taller guy. Also, when getting your suit fit, be mindful of the shoulders. If the shoulders aren't right, the rest of the jacket isn't right. Shoulders should not stick out too much and should not rumple inwards. If they do, the jacket shoulders are too big. If you stand next to the wall in the fitting room with your arms straight down and you gently tilt towards the wall....if the jacket shoulders hit the wall way before your upper arm/elbow does the shoulders are too big. Please pay attention to this; too many people don't and end up looking like they are a kid wearing their dad's suit or something. As far as length goes, when your arms are straight by your side, your jacket should hit at or around the midpoint of your thumb.
Jos A Bank is better than the designer label garbage you will find on the racks at typical department stores, but is still rather meh. Personally I think its too pricey for what you get, unless you are getting in on one of their buy 1 get 1 free/half off/buy two get 1 free/whatever crazy deals.
Men's Wearhouse is absolute trash, avoid at all costs.
I like Brooks Brothers a good deal, their fits are superior to the off-the-rack stuff at MW or JAB and the like, materials are superior and the guys in the store know how a suit should fit and what needs to be done to one to make it fit you. Guys at big chains or dept stores don't give a damn and just want to make the sale for their commission. J Press makes nice suits as well. Also, pay a visit to your local menswear shops, nearly every medium size-large city has a couple of venerable old menswear shops that will carry higher quality merchandise from labels you probably won't recognize, like Southwick.
For ties, i buy lots of 'em on ebay. Ties on the 'bay are cheap, even from places like Brooks. Buy a lot of 'em, keep the good ones and toss the ones that don't make the cut.
Shoes I would actually spend some money here. I see too many people at work walking around in awful looking "dress" shoes that havent been taken care of, all creased and marked up because its thin cowhide with stitches fraying. And most of them aren't even stiched into the sole. The uppers are just glued to an all-rubber heel. Go with something that has a leather sole, is stiched, and from a reputable maker like Allen Edmonds or (if you can afford it) Alden. 200-400 bucks for shoes might seem steep, but not when you consider these were meant to be cared for and if properly done so, will last you for 20 years. If you cant quite drop that much money on a shoe, get a decent midrange brand like Johnston and Murphy or something.
Shirts, dont really matter that much since they will be under your jacket. Just make sure you stick with a regular point collar, no button-downs. That's far too casual for a suit. Make sure the sleeve length is correct; you should have a bit of cuff showing under your jacket but that's it.
