I have to agree with Chris on this. Looking at the specification of the course/exam there is no real need to do the course, although it was very enjoyable, a week down in devon was great as total away from the office.
I did the course last October and am finally getting round to doing the exam (been moving house and stuff).
Although there is no self study material available i think that alot of the quality books available would be of help. One thing i would say that unlike the CEH i think they tend to be more up-to-date and so older text using old tools might be more of a hinderance especially when looking at command line tools that use a lot of extra commands.
When i took the course they gave us a copy of the Gray Hat Hacking, which i am finding qute useful. The course itself covers quie alot of tools but most of them are also covered in the most recent books as well.
Let me know how you get on...i am looking to book the exam for the end of november (at last!)
I know this all sounds a bit grey but it is very hard to find out information about the exam itself..hope this has not clouded this issue.
Nothing is impossible just improbable!!!