Properly shot, digital footage can do almost everything film can do, and a lot more. Just being able to shoot digital at 1600 or 3200 ISO with minimal grain means that you can shoot with 1/4 of the amount of lighting that film would need. This cuts the cost of your lighting package and makes it possible to run lights from consumer power grids. It also makes transport, setup, and breakdown a lot faster.
Being able to instantly review a take on digital is another huge advantage over film.
Why pay 2 or 3 times as much to shoot film if the real benefit in the final product is hard to justify ?
The ALEXA ST open-gate image format is 3414 x 2198 pixels, so scaling up to 4096 x 2160 would not be a huge difference, especially if they shot with anamorphic 1.5x lenses which would make the final image format 5121 x 2198 pixels.
It's a tripod ONLY feature where the camera uses it's sensor shift ( from it's IBIS technology ) to create 80 MB Jpegs or RAW images. I don't think there is any way to do this externally with photoshop. ( the camera is moving it's sensor at the sub-pixel level to capture a bunch of images that are then used to create one high resolution image and it all happens in-camera ) So the camera does NOT move while making a high resolution photo, and this can be used with any lens.
I would mount the light to the gimbal handle and NOT the camera.
There are many NetFlix shows currently being shot with the Varicam 35 camera...http://info.panasonic.com/varicam-properties.html
I would try to buy used Lowel Pro lights. They are super compact and pretty bright at 250 watts each. ( I own 6 of these )