I can put such on double layer media, then use DVDSHRINK to shrink it down. I hear Alcohol 120% has some DVD emulator but haven't tried it. Maybe you can put it there or on a DVD directory and have DVDSHRINK do the final pass.
Anyhow, this is all I'm going to write about this. It's pretty much a small puzzle that you put together.
I am at present using Dvdsanta 3.44 but it does not allow me any variation like at the moment I am trying to burn 2.25 hours of data onto a 2 hour disc and cannot as it does not have a format for doing this is there a way of doing it or is there another programme I can download that will do this.