for multiple audio tracks:
audio: aac 320 kbps (not lossless)
type: normal
container: mkv, mp4 or mov
x264: crf 0, preset ultrafast
in video settings set yuv format to nv12 (4:2:0) or I444 (4:4:4 - that's best quality but you need a fast hdd)
via ffmpeg (single audio line only):
type: custom ffmpeg
container: avi, codec: utvideo, audio codec pcm_s16le (wav - audio will be lossless)
in video settings use I420 (4:2:0) or RGB (true lossless but you need a VERY fast hdd)
for decoding utvideo you need the codec:
http://umezawa.dyndns.info/archive/utvideo/