Ask HN: Suggestion for a cheap (long) video creation AI platform?

Till today, aside the occasional ChatGPT interactions, I've used AI only for music, mostly covering my old compositions of many years ago. Now I'd like to work on an old idea using my music as soundtrack then making a video out of a story I've been cooking in my head for some time. Which service would you suggest to make a 1 hour+ long video either as a cartoon movie or a sequence of panels comic style, that is no need for photo quality, possibly alternating both? Of course I don't expect the full video or sequence and am prepared to cut and paste several sections together, sync with music, etc. The AI however should be "I" enough to maintain characters and environment consistent through the video, that is not changing faces or clothing, etc. It may appear a stupid question, but as I have zero experience with AI video, I rather ask first before wasting months for something that wouldn't work. Also, I'm retired and wouldn't make money out of it anyway so it should be as cheap as possible, I don't need fast creation times, 4K, any promotion or other options. Ideally it would be distributed as Creative Commons. Which service would you recommend? I know the technology is running at crazy speed so what someone would recommend today could be not the best one in two weeks; still better than nothing. Thanks for any advice!