I'd like to order a new iMac, 27" and I'd also like to use it with the existing articulating arm that's mounted to my make-shift desk. Are there adapter plates available to mount the iMac to the VESA plate that's on my arm? BTW, a search did produce plates for previous iMacs but it does not appear they work with the 2015>. I also found adapters that utilize the stand that comes standard on an iMac..no thanks! How are you mounting your iMac?