Combining several PDFs into one PDF with chapter breaks between each one

[kerrypolka]

First off, I'm not having trouble plugging my PDFs through Calibre onto my Kindle - so I don't think this is a conversion question (or at least, I hope not, as I understand it's a giant pain).

I have PDF chapters of a textbook that I'd like to combine into one textbook that I can navigate on my Kindle. So, currently I have seven PDFs:

ch01
ch02
ch03
ch04
ch05
ch06
ch07

which I'd like to combine into one document - textbookname - but have the Kindle recognise them as chapters.

I'm not sure whether the best way to do this is to combine them into one PDF, and somehow tell Calibre where to put the chapter markers, or to use Calibre to combine them into one document and tell it to remember where the document breaks were.

Does anyone have any ideas about how to do this?