Could I suggest a close look at the Marvin reader app? http://www.marvinapp.com/ I find it absolutely excellent in every way.
For reading it has freely adjustable fonts, sizes, line spacing, paragraph spacing, margins, text and background colours etc - you can set the appearance of the book exactly as it suits you.
It has facilities for searching, bookmarks, notes, highlighting text. It also has the most incredible "A.I." Artificial Intelligence facility. Marvin will 'read' a book for you and, (to quote the web-site), you can ..
"•Look up characters and other names in the book in Wikipedia or anywhere on the Internet straight from within the app.
•Annotate names in the book and share your research.
•Find out where a name appeared first in the book. This is great if you forgot who a character is and need to quickly look it up.
•Fetch articles about the book and author biographies.
•Learn more about the book. Was it made into a movie, a play, a radio drama?
•Find and attach links to web content such as reviews and videos.
•Build summaries of the book."

If you store your e-books from your PC in Dropbox it will pick them up from there. It also interfaces really well with the best PC-based e-book cataloging program, Calibre.

I had one instance where I required support on it (I couldn't work out what I was doing wrong with some bookmarks), and I found the response from the author to be really prompt (less than an hour on a Saturday morning!), completely relevant and pointed out my error very politely. An absolutely excellent app, free of charge, with great support - what more do you need?