Im a caliber specific believer, but Im also an NFA addict every firearm I own is either a SBR, SBS or suppressed, so on that particular AR I have an AAC 762-SD because its a 300 blackout.Very nice! What can and caliber are you running on that AR? I plan to build a suppressed SBR AR this year and would like to find a combo that works well.
Anything from AAC or silencerCo is going to be good. I really like the AAC SD, I have another one of their 308 cans which is like an inch longer and its not a quite as the SD.
If you can only go with one I would go with a 30 caliber so you can shoot a 556, but also use it on a Remington 700 or a future AR10 or 300 black.
Really anything on the market is going to be a good can assuming you are not going into war with it. Just get what you like, your going to wait about 6 months for it so better enjoy it