YHM Resonator is about the best bang for the buck I think. A few companies are doing good promotions right now so there are some other good deals.
If you're primarily wanting it for blackout a ton of options will work well. Do you have other suppressors? If not keep in mind what other calibers you would be most likely to suppress a .45 or 9mm pistol can works great for blackout and can be used on those or the .30 Cal can like you're thinking.