Here is my logo idea for your sign and brand: Entry #46
I made the dimensions identical to the 15x3 sign you will have, so you can see exactly how it will fill the space. I played off of the whole calm night-time idea, since mattresses are obviously related to getting a good night's sleep.
Let me know if you want to see any other color changes or other revisions. Thanks!
#47 - I really like this one. Would it be possible to make the crescent moon effect a little slimmer, and tilted? Maybe the crescent opening to the upper right or left?
The nice thing about angling it, is it will no longer get confused for a "C". Likewise, if you go too high with it, it could suddenly get confused for a "U". I think a diagonal angle is the best solution... either #87 or #90.