As stated above, I don't think you can specify the output chunks beforehand. The brute force methodology would be:

Pseudo code:

# foreach $file ( @files ) {
#   save off a copy of the current compressed file if it exists
#   attempt to add to current compressed file
#   if compression fails or new file size > 2GB
#     rename the saved compression file copy to the working copy
#     start a new compressed file
#     add file to compressed file
#   end
# end foreach
[download]

Of course this runs into problems if a single file compresses to >2GB