Thanks to 1gkar's suggestion, I picked up the LG GGC-H20L Blu ray drive, which came with the PowerDVD BD suite. Although Cyberlink suggests that powerdvd 8 ultra is required to play back dvds, I can confirm that this is not the case. Once I'd installed the suite and opened it, a dialogue opened asking me if I wanted to download a free update, which I agreed to. It installed the latest version (PowerDVD Ultra 7.3 BD edition or something similar??). I'm able to use it to watch blu-ray movies, as far as I can tell in 1080p (it certainly looks pretty good!), and output SPDIF audio to my receiver.

Now my question is this. Does anyone know what I'd be missing out on by not upgrading to powerdvd 8 Ultra? As an aside, I do use the pdvd codecs to watch freeview. Are there important features that I'm missing out on? Is the playback significantly better in powerdvd 8? The dark knight ran pretty much without a hitch last night, apart from maybe one extremely minor hiccup about halfway through, but that was less noticeable than the layer-changing pause you often get with dvds.