OK,
Once you have your vm session running with a valid network connection (see above), the following commands worked for me:
1 - rm -Rf calibre
2 - bzr branch
http://bzr.kovidgoyal.net/code/calibre/trunk calibre
3 - sudo emerge sync
4 - sudo emerge dev-python/lxml dev-python/PyQt dev-python/beautifulsoup
PyQT is taking a loooong time to emerge so I'll post back if I can now build after these finish
Cheers,
Crazy