To be honest, script and novel form both have advantages.
Script is easier for me to quickly prototype drafts and segments of stories. Character design and environment design is more up in the air and allows more room for error. Descriptions could be lost in translation in a script, but the pacing and scene transitions are perfectly clear for me.
Novel form would take more time for me to interpret (as I'd need to read long segments of text over and over again in order to get the right context). However, the end result might better represent your original vision of the story. Descriptions and environment themes would be clear as day. One of the problems that could come from novel form is incorrect pacing, as I'd need to go through some mental hoops to interpret a paragraph into a series of panels.
So in short: Script Form = potentially faster work plus more creative freedom on my end and good pacing story-wise, but could stray from your initial vision for a scene or the story as a whole, as there is less direction and context for me. Novel Form = slower work with a more true-to vision product as there is plenty of context for me to absorb from your writing, but the potential for the pacing to be a bit off (scenes could be sluggish or too fast depending).
I'd say its ultimately up to you as to what you send me in terms of source material. You could even change up the formatting chapter by chapter (or even mid-chapter) in order to more clearly convey certain aspects of the story to be translated into sequential art.
Shoot me a DM via these forums with whatever you want whenever it's ready. I'd totally be willing to try out a one-shot as a test run for future endeavors.