Yes I am serious. People do need reminding.
Oh, yep, great idea to get the new gear but make sure you don't leave it to the last minute. eg new shoes, ever bought a pair that gave you blisters? You definitely don't want sore feet on at your interview. Very hard to look relaxed when your feet hurt.
A new cheap suit looks just like that. Leave it to the uniform department to give you a cheap ill fitting suit. Spend the cash on a good suit. A well cut one will last for years.
Haircuts. Best to get one about a week prior to your interview as well. Gives the fur a slight chance to grow out and cover any mistakes plus the sun can get to your white bits and tan it up a bit. (not being funny or facetious. A white mark on your neck screams "I've just got a really short/tidy hair cut for this interview, normally I'm scruffy")
Done a few interviews, been successful at nearly all of them. Even sat on a few interview panels. (range of experience, bush pilot, airline pilot, now corp jet pilot)