Reading manga on PDAs

I'm considering buying a PDA (like Palm's), but one of the things I want to do with it is reading manga scans (I don't scan them myself, I download them, but I own the mangas, mind you). All I'd need is to be able to browse image files in the same fashion as ACDSee in fullscreen, i.e. setting up a zoom factor, scrolling the file with 4 keys to read it, and moving to the next/previous picture with 2 keys.

Does anybody know if this is a good idea? Any particular architecture and/or model you may recommend (because there's better software to do this, or whatever)?

Thanks