I use two apps for ebooks; iBooks for .epub and GoodReader for .pdf. I use calibre to convert some .pdf to .epub. However, when I use calibre to convert magazines, strangely, the size is reduced and when I use iBooks, the print is rather small. For iBook, you can change the font size but you cannot zoom in (unlike GoodReader). As such, iBook is really for ebooks and not for magazines.
I would send you the iBooks.ipa if you can download to your iPad. Unfortunately, I think you need authorisation and I cannot let you have my cousin's ID. If you want to give it a try, I can send the iBooks.ipa to your email but you need to jailbreak your iPad (not recommended) to use it without authorisation.
You may be right that Stanza is a good app. I cannot comment because I have not used it before. Maybe I will try it later