If you could get a consistent skin, using multiple packages/scripts would be a quick/dirty/cheap way to go.
Wordpress for the main site/layout
Clip-Share for the video
Not sure about the photo gallery/ratings, but if you look at any one of the porn affiliate forums, they have TONS of scripts you could skin.
Like I said, not very clean, but it'll get you started until you can afford your own platform.
I'd recommend Dot Net Nuke for a CMS. Very powerful with tons of add-ons and modules. It's in ASP though and it looks like you're looking for something in PHP. Something to consider though.