The new version we are working on at this moment has user definable output size.
Unfortunally you will still need IFOedit to put it back into one DVD.
If you want to do it all with
DVD2one you will have to wait until we are ready to release the version with 1:1 copy support.
(it's the number one on the todo list, so you can expect that feature soon, but i can't give you a timeframe)