Thanks for all the replies CMDR's this has been helpful. The EDTracker is looking damn good at the moment. I'm not bothered about it being perfect as I'm looking for a cheap alternative until the Rift goes retail.
Have a quick look around their website, its a few people who worked it all out, and they are making them in their spare time to help out people that can't / don't want to, before they started selling the ready made unit they were telling people where to source the parts and software as well as posting how to videos.
I am pretty sure they come with the software preloaded (the term "flashed" rings a bell), and I saw a GUI in a video that would suggest its reasonably easy to set up.
If you want to PM me I will let you know what I think, mine should hopefully arrive in a week or so.
I know there are lots of older threads covering the subject, but I would be interested to hear how people with the ED tracker are finding it since launch, it looks great in all the videos I have watched.