Preserving the structure of the XML file

Colleagues:

Does anyone know if there are less-lossy XML parsers and serializers 
that can capture and reproduce the structure of the input XML file 
including tabulation,whitespace, etc. ? We would love to know about
experiences with parse/serialization approaches that have a greater 
infoset than that provided by SAX and DOM, especially related to 
ignorable whitespace and attributes ordering/whitespace.  We are editing 
XML and want to preserve the file as much as possible.

Kind regards,
Oleg Dulin
Opence, Inc.