Does LMU still supply students with Nordian text books?
Yes.
Are the latest editions any better than the previous? I read that the books have spelling and grammar errors.
The latest edition is the sixth edition. I can't tell you whether they are better than the previous versions but I've been told they do include the new matrerial for when the syllabus changes later this year.
Personally so far out of Module 1, I've found Principles of Flight by far the worst written, so my advice is go to a pilot shop and ask to see the PoF books from each provider that the shop stocks and compare them. If you think the Nordian version is fine then you will likely be okay with the rest of their books.