So, I've done up a set of paperback covers, modified from the dust covers by RandomPinkiePie
viewtopic.php?p=1002#p1002. They are still a work in progress, but here they are:
http://imgur.com/a/Vi5hk
Paperback covers for 6x9in books. These are in .jpg, but I have the psd and tif for HQ shininess. The measurements in these still need to be adjusted to ensure nothing would be cut off during printing, but I have yet to get around to it. It was my backup plan just in case the project fell through and I had to do it myself.
If there are plans for paperback and people like these, I'd be more than happy to finish them up, re-size them to whatever is needed. Or if anybody just wants the psd files. Just let me know.