I would suggest converting your comic ebooks (or .cbr / .cbz) to .pdf format, which usually scales better than just .jpg images within a .epub ebook. See my wiki post
here under
Niche_Uses about exploding a comic ebook into just it's images and then using
img2pdf_v0.2 to easily combine them into a .pdf ebook.
For my LCD Reader (
Next1 ) that supports Adobe Mobile Edition 9, I can view .pdf ebooks in landscape mode and then select my zoom level to "Fit to Width". After reading the top portion of the page, I can scroll down with the arrow keys (it micro increments so it's best to hold down the arrow) until I reach the end of the page. Then a page button advance brings me to the top of the next page
and repeat!
See this
post to see what can be done when reading .pdf ebooks.