The one reader I never see anyone mention is iSilo.
www.isilo.com
It's cheap, smallest file size I've seen yet (free convertor), and speed is instantaneous. It can convert .DOC, .TXT, .HTMx and I think one or two others into .PDB, it's own format. It's constantly being updated and has all the features you need. Definitely check it out.
-Kensupen