I've used ktorrent, azureus and rotorrent.
ktorrent is nice and lightweight (using KDE already though) and has a good sceduler, but i had trouble with allowing access via iptables.
Which is where azureus came in, it seems to handle everything through the same ports (tcp/udp) although i haven't looked into scheduling yet, it's a bit heavier due to its reliance on Java.
rotorrent i found to be the fastest/lightweight. Like stated check out the documentation, but it's pretty easy to specify the required switches in the command, It's also very useful for using over SSH.