I have an Extang Black Max on my Chevy eztended cab, short bed. You can see it here:
http://www.extang.com/blackmaxindex.html
It has snaps on all 4 sides so it can be completely removed as opposed to the kind that just roll up. It was about $200 and it was very easy to install.
If I had to do it again I might go for the Extang Full Tilt cover which is around $350 or one of the folding covers but I think they are around $500.
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