Looking for some advice as I'm replacing my old PC that we've had connected to the TV for ages.

Have been looking into various options for this.  All I really want it to be able to do is:

 

• play video files from my external hard drive
• be able to download movies and store them on my external harddrive  
• use tv/music streaming services like TVNZ on demand, skygo, lightbox, spotify etc

My initial thinking was to go with a very cheap chromebox or chromebook, but now I understand that those won't work with lightbox (because that service uses silverlight).  I suspect that I wouldn't be able to install a bittorrent-type programme on those either.

So is my best option just to buy a cheap laptop?  That will have way more functionality than I need, but it doesn't seem like there's anything with less functionality that still meets my needs.

Appreciate any advice here.