Their are plenty of metric mounts from silencerco/SWR. The osprey 9 would be a great choice for a very quiet can that won't block your sights, if it ever needs cleaning silencerco will clean it for free. The SWR Octane 9 is a user serviceable can which is very quiet, but it is round which means your sights will be blocked some, but the ability to disassemble and clean it can be vet important if you ever plan to shoot 22lr or lead bullets through it. Again they both have metric threaded pistons available.
The thread pitch you have is the main thread pitch I use. Ive noticed on folks who have 1/2x28 cans that they have to make sure its tight on the regular as that thread pitch seems to come loose sometimes. Ive never once had my can loosen on my 13.5x1LH pitch. I bought the ISIS-2 along with having already an AAC evo CQB 9. Should have the isis-2 soon. Love me some metric threads.