Detail coding for Email sending website

I need someone who can help complete and edit some code that i already have. I am developing a website that sends large files of up to 2gb to a persons email. I currently have some php code that uploads a file to the server but it doesnt work with files over 30mb. So i need to reengineer this to make it upload files up to 2gb. I will provide you with the code i currently have. Also, i need to do it in a way that once uploaded to the server it automatically deletes itself once downloaded by the recipient or deletes itself within a specified amount of time. The other assistance i need is uploading advertisements. I want to make the user view an advertisement once they click send, they have to watch the advertisement to the end before being able to upload the file. So i need some sort of verification code incorporated into this. So that experience is helpful. Like i said i have alot of the code and the basic website already made. I just need more of the backend coding done. Must be affordable and able to complete project within in a couple months.