Hi Tim
There are no alternative publishers for the actual regs etc and frankly I fell they are a bit of a rip-off. If anything, they should be provided free, but I don't wish to court controversy.
The latest actual regs have a blue cover and do not make light reading, but are THE source of reference for any electrician. Generally, the On Site Guide is the natural companion to the actual regs and most courses, AFAIK, would specify both as course materials. All my course notes refer to both.
The OSG is certainly more readable than the actual regs themselves but it depends what use you are looking to put them to. If you are just wanting to get an understanding without actually doing the course, then I would think one of the many books on the subject are better suited, since they are less likely to be written in 'regs-speak' - another language altogether sometimes.
It is worth remembering that the regs are not law. They are not statutory. The idea is that a 'Competent Person' can interpret them to provide the safest design and installation of anything electrical. The definition of a Competent Person is another can of worms waiting to be debated!
HTH Rob