Big +1. I like the looks of the FH556SA a little better myself as it reminds me of the look of the HK flash hider, but if you may ever run a SF can, the 212 is much more versatile.I like the Surefire fh for the 416. It'll get you to legal length.
SureFire FH556-212A Suppressor - Flash Hider/Adapter
All of the ones mentioned are 1/2x28 (AR15) threads. Also if one were to cut a barrel back, he could choose any thread pitch he desired.I would have said AAC's MITER system, but it's apparently not available in metric thread. I would try to get ahold of them and see if they are making it. Otherwise, the Blackout 51t.