Dedicated Bittorrent Downloader
 

Scenario:

I know that a NAS can do what I want to do, plus more, but I don't wish to spend hundreds more on features that I don't not need now (for ex. RAID). I am strictly looking for a device that can attach to my Linksys E4200 (Tomato) via Ethernet and download torrents (on-demand or scheduled downloads). It needs to have it's own bittorrent management software that can connect to a VPN or Sock5 Proxy. I need it primary as a network-attached storage media, other features like DLNA, iOS, Android, Cloud Storage, would only be bonus.

Is there an external HD that fits my criteria?

I have a Raspberry Pi. I was considering of using that as a budget NAS, but I don't want to deal with Linux anymore.

Most NAS already have built in BT function

Buffalo makes a external HD with network input so it's a NAS, but it's relativity inexpensive and has dedicated BT client.