How to establishe torrent site?

Hi!
I have idea of making website that works like torrent download site. And I have 4 questions for you.
1.Where to get script?
2.How to publish script?
3.Best possible hosting network?
4.How much money I need to invest to make site like that work?

Thanks for any advice and help!

I have some kind of that script.
Better to host a vps.