Thanks for the mono mix, ChainsawAsh!

As far as using AviSynth to create a cleaned up, anti-alias'd, anamorphic GOUT, I'm pretty sure it can be done on a Mac. I use one myself, and I was worried for a while that it wouldn't work, but after reading around I discovered that AviSynth, DGIndex, and HCEncoder will work if you use Crossover/WINE. I have these installed currently and it went without a hitch (although I haven't actually tested them since the encoding takes so long). I'm not sure if all the other programs you'd need also work, but there are Mac equivalents for many of them. I'm confident that I'll be able to get a better version of the GOUT up and running.

If you need AC3 for your DVD's, I recommend Wav to AC3 Encoder 3. It also works like a dream in Crossover. The encoding scheme is based on the ffmpeg implementation, but it has many advanced settings for achieving the maximum sound quality, which are described in detail in the settings.