Bought this $10 cover, and am pleased (took 10 days to arrive):
http://www.amazon.com/Magnetic-Folio.../dp/B00DDMN73E
Really, really, really like the sleep/wake up cover option... Now I never have to dig for the non-protruding power switch... And I can just collapse in bed without having to worry about shutting it down.
Reflow of PDFs is a non-issue for me. While Sonys do reflow the PDF page breaks are still intact, so some pages on the ereader will only have a few lines... I found it so annoying on the first few PDFs I tried it on I never did it again. Either accept the PDF as it is [after cropping] (complex formatting or graphics), or convert the text to something readable (epub).
Best ereader I've ever owned! ... My sole complaint is the big "Page XXX of YYY" on the bottom that never disappears. However, I know that the patcher can fix this if I spend more time on figuring it out... Reading text now, so it's not a big deal. Once I start reading PDF or image epubs, the "Page XXX of YYY" will have to go!