I'd say whichever works best for you personally or calls to you in some way will be the right one. Regardless of which you choose, you'll want to add in a grounding stone such as hematite or smoky quartz to help keep things stable.
Of those you listed, I find Amazonite to be the most useful in terms of clear communication without compromising my energy level. Blue agate is calming to point of sleep for me, and as such would not be a stone I'd want on my body during an interview. Aquamarine does nothing for me so far, and though Fluorite is supposed to be a powerful stone, nothing's changed for me since bringing quite a bit of it into the house. But everyone is different.
There's one form of Amazonite that I sometimes see called "graphic Amazonite"--it has visible layers or inclusions of smoky quartz and sometimes black tourmaline. One that had both these additions would seem to me to be an ideal stone for your purpose, if you have or can get one easily. Below is an example from my collection; it's really too big to carry around comfortably! But a pocket version would be an excellent thing to have on hand. You can see both the black tourmaline (the almost opaque black spots) and the transparent smoky quartz threaded through the blue amazonite. It's neat stuff; this one lives on my desk, where I do most writing and make any calls to businesses or doctors, etc. I have a tendency to want to hold it or have it in my lap; as I can't feel crystal energies (only their results), sudden desires to have a stone on or near me are how I tend to choose, and only later do I look up their uses and find that it was exactly what I needed. That's how this one ended up coming home with me in the first place, and it's turned out to be an excellent "let's get down to business" stone.
But if you have the crystals you listed on hand already, I'd say pick the one or two you feel you work best with, and then add something grounding to it. Let them know what you need from them, in whatever fashion you prefer to program them. If you're not carrying something separate for the job hunt, I'd also pr've had probably put a citrine in there.
Good luck with your search!
~jolie