5.1 on a Macbook 13.3 White?

I have a 13.3 white Macbook and I regually connect it to my TV to watch all of my films and TV shows etc. At the moment I am using a standard 2.1 from the headphone jack. I wanted to upgrade to 5.1 and maybe get a theater system so I can watch/listen to my films and also my xbox the way they are meant.

I was just wondering if there is a way of getting 5.1 out of these Macbooks. I've seen those USB sound cards and think they maybe the way forward.

Does anyone know/had the same predicament and if so can you recomend one?