Finetune AI Writing Style

Need someone to help me train an AI writing model on a whole bunch of transcripts from youtube videos. Your job will be to fine-tune and train the model, so that it is able to write any other topic in the "style" of the given inputs. (9-10 different content creators, and the data/transcripts have already been prepared)

If interested, title your message back with "Finetune Youtuber Writing Style AI Application" and these points addressed:

1) How would you approach curating and preprocessing a large dataset of YouTube video transcripts for training the AI writing model? Please describe your methodology and the specific tools you would utilize in as much detail as possible.
2) How long do you estimate this task to complete? Include your quote for this gig.
3) In your opinion, how many video transcripts would be necessary to ensure the AI writing model is properly trained and achieves optimal performance? (as we prepare to scrape the data sets)