Yes - Those are original (passive, non-shielded) Diamonds...
The mounts are TV mounts from IKEA. Very cheap - Around $25.
Limited horizontal and NO vertical adjustment - They have to be hung at the right height, but can be horizontally adjusted fairly easily.
I think they support up to 40 pounds... I'm pretty sure I had my 824's (for the short time that I had them) up there... Definitely the BX8's... JBL S38's... B&W 602's... SB-CR 55's... Those stands have been host to a bit of a collection.
I think there's five staggered holes to drill in wood/drywall screws... Just make sure they hit some stud on the way. Drilling and extra hole in the center wouldn't hurt either. I think if you're centered properly, you're going to strike gold with 2-3 screws.
ALSO - A small piece of neoprene (such as a mouse pad) would be a good thing to have under the speaker - It's a metal tray, you know...