Torrent client for the command-line?

Deluge is controllable by gui, web, and console.

To setup remote access to a deluge server see the thinclient guide.

deluge-console

deluge-gtk

deluge-web

I think the default torrent client transmission itself has a cli interface and can be installed with

sudo apt-get install transmission-cli

I use rtorrent on a headless server to serve Debian and Ubuntu ISOs, works quite well and can saturate my network link. Dependencies and memory usage are minimal.