I like the Sony but the Kindle is very popular...all have Pros/Cons
I would not recommend a touch screen unless you cover it with replacable screen protectors from the onset...
There are some very nice free programs that will re-format many different fomats of text files so you can download from the Internet and read on the reader...
When they first came out there were many different formats and they were not all compatible with each other... the new standard format is ".epub" there are free programs that will convert all older formats and web based file types like HTML, PDF etc. to .epub