I love from Kjots the way you can have books and pages to make notes so you can
easily keep your records of anything.

However, I find it a bit limited since as far as I know you can only put text,
but not to add images, equations...

Among others, I think this would be particularly interesting to keep records in
research.

What I'm thinking of is a Kjots philosophy (of course integrated in Kontact)
and with all the power of Koffice!

I requested this feature already:
https://bugs.kde.org/show_bug.cgi?id=252554

Have you had a look at BasKet? I'm not sure whether it can do all the things you describe but I think it's much closer to what you want than KJots.

BasKet is great but I find it a bit distractive as well, maybe because I didn't use it before. BTW, it's still being ported to kde4.
On the other hand, I found Silence, which is pretty fresh but very nice though. It would be just what I need if it could be integrated in kontact!!

Because of the mention of BasKet in this thread I downloaded it and, after a BRIEF trial of the examples, will be using it.

It is elegant, and graceful, as are....all KDE apps........

woodsmoke