I was thinking of offering these as like custom sketchbooks, or "art journals" (with lined paper and stuff in) - so people can have a mixture of different papers to play with. You pick your types of paper, number of pages, and your cover, corners, decorations etc, and I put it together. Opinions? I'm putting a webpage together with the details.
Incidentally, yes, it's not JUST a diary; there's a "Nanowrimo" page for me to record my word-count in November, an adresses section, a page for mandatory training (as there's so MUCH of it now, I can never remember when I've done it all) and a place to write down when I've been on-call. I used fairly good quality sketching paper so it was a bit more durable.