m-audio 410 firewire for surround?

Hi, i'm planning to buy a soundcard for a surround system,
seen I just have 5 yamaha mps3 monitors and a sub.
So, could the new m-audio firewire 410 be a good choice?
I'm using a mac powerbook with osx panther,
and know there are drivers for it, and should also support dolby ac3
surround to mix up 6 channels.
My only question: with it can i play dvds in 5.1 with panther
dvdplayer (it supports dolby digital) or i need an internal/external
decoder?
I have a lot of concets in dvd so would enjoy them
Bye