The iLiad is your only option today, but I am not sure about "40mb - 200mb" PDFs. I suggest you post a question in the main iLiad forum about PDFs this large. See also liad to buy or not buy (mainly for pdf)
and my iLiad cannot read this pdf?
For images from PDFs on the iLiad, see Photos from medical journals
, but note that (a) the screenshots may be rescaled by your web browser (click to get full size) and (b) the iLiad's pixel density probably higher than your current screen (so the images will be bigger than on the device).