Thoguh the official client is alright, may I recommend using a more feature rich client such as Azureus? Azureus normally gives me better speeds than the official client and that is worth the aditional needed RAM imo.
You can even run it on a headless (On a server or whatever) and only controll it from the command line if you want to, they have a tutorial on their wiki for doing this.
I normally just run azureus in a screen session, and whenever i want to add a torrent I just ssh into the server, attach to my azureus session and type a few commands, works amazingly well.