I just bought an iPad to use solely as an e-book reader for my textbooks. They range in size from 16 mb to 800 mb for a total of 6 gb. Every program I've used--iBooks, GoodReader, CloudReader and Stanza--has crashed immediately upon opening any file over 100 mb. Is there an app that could handle big files, or should I go back to the MacBook? Any help is appreciated.