Selling shares of an Ethereum-based NFT

I'm building a content platform where content creators can mint their own NFT to represent their work. The one aspect I'm also trying to build out is being able to buy shares in the NFT. So for example, if a creator says I need X dollars to do this project, they can sell of a portion of the budget to investors in return to splitting the ad revenue made against that content and giving it back to investors. So for a $1000 project, they can sell up to $750 of that budget as shares to users on the network. It's crowdfunding, but getting a return on their investment.

Curious as to how this would be done and what type of tokens I would need to set up. I'm assuming ERC-721 for the actual NFT, but would I just create a regular ERC-20 token for the tokens needed by producers? So producers send their ERC-20 tokens to buy shares in the ERC-721 NFT created by the content creator?

thanks in advance!