Ridiculously Fast Physically-Based Turntable Renderer on Linux (Headless, Command Line)

Hello! I'm looking for someone who has experience rendering scenes on command line/headless via cloud servers (e.g. Amazon EC2, GCE, Azure, etc). We'd like to: (1) set up a scene with your help (can use a Windows/Mac/Linux machine with a screen for this part) (2) save it out and transfer it to some flavor of a headless Linux server (Ubuntu preferred, Google Compute Engine with an Nvidia K80 preferred) (3) run a command line program to render out a turntable of screenshots at 3840x2160 resolution Requirements include: --The turntable should allow us to adjust the number of screenshots dynamically and should handle the rotation between shots itself, e.g. we put in "20", then it rotates the model 18 degrees each time and takes 20 screenshots and saves them out in a specified folder. This functionality should be controlled by either a configuration text file OR via a command line argument. --We need to hot-swap the model that will be placed in the scene (e.g. when we run this command line program, we need to be able to either (a) define a different OBJ file to import, or (b) replace the OBJ file it is pointed at with a different one. --The renderer needs to output screenshots at a *minimum* rate of one screenshot per second (SSD-based instances, Nvidia K80, one 20,000 face model, one 200,000 face model, 8k textures for each model). --The renderer you use needs to either be free OR have a license that we can purchase for a reasonable dollar value. --The renderer needs to output screenshots that you're proud of (that look awesome) and look as realistic as possible. We've tried using Marmoset, Unity, and Unreal so far, but haven't made it very far with any of the three internally, so we're looking to you to help us define what the pipeline will be and how we'll be able to get ridiculously fast renders out of it. I look forward to working with you :)