I have looked at quite a few different methods to process comic files (.cbr & cbz) for reading on ebook devices and been unsatisfied with the results. I recently upgraded my copy of ComicRack (http://comicrack.cyolito.com/index.php) and discovered that in addition to being able to convert into .pdf ComicRack also allows you split double pages, adjust resolution, and make changes to contrast & brightness. It doesn't convert from color to greyscale, but with everything else that it does it might be worth a look.

Thanx for the recommendation. I am trying ComicRack right now. Pretty good.
As to reading comics, I guess I will stick to MangaMeeya and MangaMeeyaCE. IMHO, It's the most advanced comic reader on MS Windows XP and Windows Mobile, although the auther had stopped to update the software at least three years ago.