Good choice! Like you say, you may not get another chance with such a good 5" device.
PRS+ link:
http://code.google.com/p/prs-plus/
I think the Sony covers for the 350 are really, really good. Both the lighted and the non-lighted. I started out with the lighted, but later bought a non-lighted as well and I now prefer that unless I suspect I'll be needing the light. (I kept my eyes open at eBay for a good bargain and finally it showed up.)