I do my video editing on a lesser PC than yours.
I have tried lots of software out there, but my absolute favorite is Pinnacle Studio (currently V8). www.pinnaclesys.com
It will let you pull the video out of your firewire port, overlay all the sounds you could want and write it out to VCD/DVD etc.

Personally, I love the timeline type interface which I find to be very logical.
The other good feature is the music overlay which will add music to exactly fit the length of video, complete with start and finish.
The selection of wipe and fades etc is also really good.