Looking for Custom built or pre-made tube site

Hey guys,
I have started planning a tube site and was hoping you guys can help answer some of my questions.

Some things I need it to do is allow people to become free members to upload videos which will be submitted for manual approval and for the members to see the views on their videos. I also want them to be able to rate and comment on videos.

All uploaded videos should be lowered in quality for everyone to see and left in original quality for paying members. So it will need a paid members section with the higher quality videos.

I want the ability to control ads on the site w/ the ability to set in-video ads. Perhaps even set it up with a third party ad provider.

I have been talking to some coders and some are telling me they want to write this in php while others say php would be too slow once traffic picks up and want to code the whole thing in python. Their prices are also quite high for this project.

Is there something a bit more practical out there? Perhaps something pre-made that can still be customized?

I would really love some of your suggestions mates
Thanks in advance