PDF zoom in and out

[wholloway]

I know this has been discussed quite a bit, but I want to make sure I am getting the correct reader. I have a large collection of PDF files that are two or three columns per page with figures and equations. I side loaded them onto my NOOK but can't read the text when viewing full page. My only option is to increase the font size, but then it scrambles the columns and the figures move around. Time for a new reader! It has to be E-Ink, take a SD card, and allow me to zoom into the pdf page. Anything else is just frosting on the cake. Send me some options.

Thanks
Ward