I think those lenses will all deliver good enough IQ, especially if you are planning on doing video recordings.
What I would suggest you do is follow a plan:
1) Decide what kind of photos you want. Do you want 3/4 body? Shoulders and up? I think 55mm is best for intimate shots, for example face-only portraits. I would use 40mm for waist up photos (and I have). With a 55mm you have to stand pretty far away from the person to take a body portrait
2) Do you want the photos to looks dreamy, beautiful, or do you want them to look documentary, realistic? This depends on the genre of what you are doing. You can't have glamorous photos of people when they are talking about bad life experiences, for example. Interviews are usually not meant to make the person look great, but to convey some truth. So beautiful bokeh might not be important.
3) Do a test run with a friend, see how it works out. Maybe you think a 55mm will be great, but on the terrain you will notice that you don't get the whole subject in frame. This is very important, you don't want your first time to be for real, because you will make mistakes
4) Write down the settings, distance and angle from subject, and camera height (are you aiming up, or down? What if the next person is taller?). Maybe sketch the frame ahead of time. Shoot Av. This will help you keep consistent with all your subjects and make the photos look like they all fit together into a series. Unless you want every photo to look different
5) Think about using tripod and flash, these can make photos look much more "pro." Exposure bracketing, deflectors, fill flash, flash diffuser,.. use everything.
I would suggest the 40mm XS, so you can stand closer to the person and get a good modern rendering, sharp and contrasty, more documentary than beautiful. Make sure you have a good WB so people look normal
Don't worry, it will get easy once you get started and look at some results