VOBs are limited to 1GB? Cool! I thought that they were much larger than this. Ok then.
Just take a look at any Video DVD - the videos are all split in 1 GB hunks.
Edit: If i burn the DVD using file structure, will it be readable from a stand-alone DVD player?
Dunno about burning on Amiga, but usually you need to select 'Video DVD' as target since there's a bit more to it than just the file structure.
Actually most DVD players I've tried don't take it so critically though. ;-)
(Single layer that is - dual layer requires some special handling of the layer break.)