Benjamin, without knowing your CPU or what type of FX you're applying, it's really hard to say.
Having said that, my previous computers have dealt with more than that from an FX standpoint.
As long as you're OK with longer render times, it's no problem.
As far as a file type, DVDA prefers MPEG-2 and AC-3 files.
Make sure both have the same name and are in the same folder.
That way, when you load the video file into DVDA, the audio will automatically follow.
My rule of thumb is that if the video is less than 70 min. long, I use a custom CBR (Constant Bit Rate) of 8,000,000
Anything longer and I use the bitrate calculator found at
http://www.johncline.com/bitcalc110.zip
