wireless router + modem with support for downloading with pc off and sharing audio video throuh DLNA

Hi,
I am trying to find a wireless router with modem for my home with features like
1. downloading torrent files after switching off pc.
2. downloading youtube files after switching off pc.
3. sharing these audio-videos even HD video through wifi and DLNA

the idea is to create a home cloud with all media files stored in one place which can be accessed through computers, DLNA certified LCD's.

thank you