I have limited S8 and S16 film experience from what now feels like an eternity ago. I follow film formats as I'm a film nerd though. One word of warning, you are going to need a shit tonne of light if you want to get low grain images with medium speed film and it really all depends on the quality of the pieces in your workflow.
I don't fully understand your remit. Is this a theoretical piece, or is it getting made? Do you have constraints, like budgetary, time, crew size etc?
Personally I like the look of Kodak3 500T (Walking Dead) with Zeiss Super Speeds. That's shot on an Arriflex 416 (super 16). S16 is much cheaper and easier to handle, and still looks awesome. Search IMDB for some of the movies with your favourites looks, and click on the technical specifications link to see what it was shot on. That way you can learn your film stocks and what you like.
However, if you're sticking with 35mm, what aspect do you think will fit your narrative best? 1.8, 2.39 are the common formats. If you're going 2.39, do you want scope (anamorphic 2x squeeze) or S35 (3-perf pull down)? Anamorphic has an amazing look, but it's challenging to shoot with. What about the processing lab, how are you going to handle rushes? Are you going to make 2k/4k intermediates, what about master? Back to film, or 2k?
Consider sound. Film is noisy. You'll be recording externally. Shooting long will help reduce noise pollution, but a good blimp/barney will shroud a lot of noise, but can make the camera op difficult.
Btw, without trying to be too pedantic, but you can't shoot video on film, or film on video.