Your bed is the vocal point in the room. What kind of bedding do you have? What else is in the room and how big is it?

You don't want your headboard to disappear into the wall. The bed and bedding sound lovely. Do the wall a contrast gray to the headboard so it will pop.

I love multiple shades of gray in a room and think the paint colors above are great. I agree that you want to makes sure there is at least some slight variation between the headboard and the wall. I don't think the headboard has to pop or contrast, you just want to make sure it does not totally disappear. It is hard to tell on screen, but I say go with which ever color above is darker.

just read about your sidetable. left paint color would go with gold (and yellow) better.

Go with the Kendall. Either silver or gold will work with accents. Also white lamps will look great with your white bedding.

I used Kendall Charcoal in my bedroom in my last house. You should use one more coat than you think you need.

BM Iron Mountain is a really nice color as well. I used it in a different room.