Hang on, I thought about it and decided it would be better to use a high bitrate 2.0. The 5.1 is just an upmix anyway.
Also if you remember, I decided against using hairy_hen's mix because it deviates from the original. So I'd prefer if we could use Belbucus' stereo, which, to my understanding, is pulled straight from laserdisc without any changes, so if encoded as a high bitrate 2.0 AC3, it would be the same audio as the GOUT, only way better quality.