Hi guys,
What website or platform do you guys use for short ai video creation?
Greetings,
Mike
Google Flow or Higgsfield as it has an option to choose different models 
We used Google Flow for this experiment awhile ago:
I use https://www.magnific.com/ (formerly Freepik). They are pretty cool and you can sometimes get deals throughout the year on their plans (like Black Friday deals and whatnot).
You can also use multiple models to generate videos.
For talking heads, make person in mid journey - then go to HeyGen and animate - works well and not a lot of $$