I gave up on macports back when I was first setting up the calibre build VM as I found that I couldn't quite get things to build exactly as I wanted them, particularly with regards to universal builds. Things have improved since then (this was nearly two years ago) and if you use 10.6 you dont even need universal builds.
Basically, the first few things you need to build are
expat
freetype
fontconfig
libjpeg
libpng
libreadline
python
Qt
sip
PyQt
after that it mostly doesn't matter (I think)