You don't have to own an FFL to buy a suppressor. And if you have a Class I FFL (standard dealer FFL), then you can still buy a personal suppressor for yourself, but you have to go to a Class III dealer and go through the exact same paperwork and hassle as everyone else does with a Form 4 transfer. Being that you are not a Class II or Class III FFL, you cannot simply Form 4 dealer transfer a suppressor to your FFL for you to use. Basically, what I'm saying is, because you only have a Class I FFL, that won't help you at all when it comes to purchasing Class III NFA items. You still have to go through the same exact channels as a consumer buying one from a Class II or Class III dealer.
That being said, if Trump would get the Supreme Court to pass the Hearing Protection Act into law, suppressors would be treated and classified as standard firearms, so anyone who has a Class I FFL could order and sell them. And just like a regular firearm, you fill out your 4473, they call NICS, you get approved, you pay, you leave with it that day. No more stupid wait times, and no more stupid $200 tax to pay on top of the already ridiculous prices some of these suppressors cost.
Also, that brake that's on your rifle is made specifically for use with a Thunderbeast Arms (TBAC) brand suppressor. I like their Ultra 7 and Ultra 9 series suppressors. Very well built, and very little (if any) POI shift when shooting both suppressed and unsuppressed.