I’ve never used Carbon Coder, so I can’t comment on its capabilities, it does seem optimized for multiple core cpus if that is a consideration.
ProCoder has a good reputation for low bitrate mpeg2 encoding, and I have preferred using it to MainConcept. Been a while since using MainConcept for me though…I believe it was their 1.5 encoder version.
Any particular reason to stick with pcm audio? It will take up a lot more space than ac3.
Remember to use only Verbatim dual layer disks. They are the only ones we recommend around here.