Those are my favorite. I used those a ton in grad school and I highly recommend them. The only downside is that they are pretty large.

For my walk-around notebook that I carry to meetings for notes, etc, I use a quad ruled Moleskine. The pages aren't numbered, but they are permanently bound.

Does anyone know a UK supplier for these or similar?

I've been after a decent notebook for about 10 years but all you can get here is crap.

Thanks for the tip - nice notebook - I wish I could get a nice hard cover book WITH numbered pages.