Arcam 27am setup

Hi, My system consists of a B&K Ref 50, 5 speakers + sub, Rotel 5 channel amp. I want to get this right because I bought the 27a to do my redbook cd's and dvd-audio 1st and video 2nd. Do I set the audio output for Bitstream +6 ch or go with Bitstream +2ch? I am using the second set of outputs for direct 2ch cd's. I have the 5 channel analog hooked up for dvd audio. My question will setting the bitstream to 2 channel mix down the dvd audio signal as well? By the way for anyone considering the 27a It really does redbook nice...nice picture too, now if I can just get used to the dvd audio mixes.. Thanks