Hi,
I have read the project, did some research S3 documents for creating a bucket via PUT method, and making it public. That was the missing element for working on your project. I have written JavaScript code to upload files from webpage to S3 bucket using directly. So, I can port that snippet back to PHP; pretty simple project. By the way, I will customize the PHP function to accept 3 parameters, AWS Access Key ID, Key Secret, and the file name for your HTML file.