If I were you, I would get an Android e-reader (Sony T1 / T2 or Nook).
They can be rooted, and then you can install a 3rd-party app to read the pdfs. I understand ezpdf is very good.
See this link for pdf handling on a rooted and unrooted Nook:
http://www.youtube.com/watch?v=ayAcdHuI5hw
Nooks root better than Sonys (i.e. are more stable). The T1 is probably easier to root than the T2. If you go with the Sonys, check they can run good pdf handling apps when rooted first.
If you don't want to root, consider the Sonys. Even unrooted, the Sonys at least provide text reflow (don't know about the Nook). Do not touch a later generation Kindle or a Kobo. They do not reflow.