[Cootey]

When I used to buy manga from Kindle all the time, I would use Calibre to do my converting. KCC is best for converting manga for consumption on a Kindle. Since I needed Calibre to strip Kindle DRM, there was no point to me involving another app in the process.

When I buy HumbleBundle comic/manga collections, I use Calibre to fix the metadata. (HB is so sloppy.) I do no conversion.

You don’t need to convert CBZ to kepub.

For what it’s worth, I don’t do much conversion anymore since Amazon made their DRM changes. I just buy manga directly from Kobo. When sideloading, however, if the comic or manga is in CBZ, I load that directly into my Kobo. If it’s epub, I load that directly into my Kobo instead.

There was a time I wanted everything to be the same format in Calibre for aesthetic reasons, but both EPUB and CBZ are zip wrappers, so I’d rather spend time reading than being tidy.

I’m not sure how to answer your metadata question other than I select a bunch of manga and edit their metadata en masse if they’re in the same series. Can you give us more details?