Legal Downloads, Ringtones etc..

I'm thinking about a Uni project to do with wap etc, I was wondering if anyone knew or could guide me in the right direction, since I've seen some people on here have a site selling tones.

Who would I need to contact to set up legal downloads?

How much would it cost a licence per tones, batch of tones etc?

Where do I get Ringtones (content) to sell, do I have to make it all?

Are there any hidden legal issues?

Any problems you have had with setting up such a service?

Is it better just to use an affiliate program?