The Sony S545 is probably a good choice for you. A couple of other negatives for SOME people (but maybe not you). No card reader to extend the memory. Has speakers built-in. I don't know the quality of the speakers, but seem like a bit of a waste.
You mention that the Sandisks are unreliable. Just wanted to mention that the Clip/Clip+/Fuze are reliable in my experience, but they don't have the battery life that you are looking for. Of course you could be talking about the Sansa View which is rarely recommended here at ABi.