Bookeen and Bookeen only. The Bookeen has been designed with A4 paper in mind and yes it can do PDF.
http://www.beachcamera.com/shop/prod...sku=BKCYBPE10W I don't own one but have spoken with other bookeen owners who have bought the reader for the reason that it can do A4. I use a Blackberry Storm 9630 and a Libra Pro to do my book reading not a bookeen and I have no stock in cybook that makes to bookeen.