Unfortunately, this is not, entirely, correct. When I left, in June 2014, one could, legally, purchase a moderator and use it; just not for Stalking.
Well - Yes and No. All silencers are considered an NFA (National Firearm Act) Class 3 controlled item, the same as full auto machine guns. However, they are also subject to state by state regulation. In some states (Illinois - home to very stringent gun control regulations) they may not be owned or possessed, even with National approval. In other states you may have one, but only use it for target shooting. In the most freedom loving states, you may hunt or target shoot with it, but sometimes there are restrictions on the games species or times (for example, no night hunting).
In all cases, the Federal process is much akin to your FAC process, with some very stupid differences. First - you must go to the store and purchase the specific silencer you choose, down to the same serial number. In other words, you cannot go purchase an Acme 101, you have to go purchase ACME 101, Serial # 12345. You pay for it up front, then receive your paperwork. You then grab your applications paperwork and trundle to your Chief Law Enforcement officer for the county (who may or may not approve of silencers) and be fingerprinted, back ground checked, and approved or denied on all of that along with the CLEOs personal opinion. You will pay whatever fee that particular office charges for this. Then you trundle back to the seller, and complete the final steps of the application and write a non-refundable check for $200. This package then goes off to the Federal Inspectors and takes from 3-12 months to be completed. The seller will then call you at some point in the future, with either good or bad news. Assuming good news, you then go back to the seller and complete the final transfer paperwork and take the silencer home with you.
Should you decide to cross a state line, you must be certain you are in compliance with that states laws, and if you are planning to remain for any length of time, you must submit a Form 20 informing the Feds that you have moved the controlled device.
Now to demonstrate how asinine the above process is - I possess a Concealed Carry Permit (which means that my background is checked every month) and I can go into any store, select any firearm I want, take it to the sales counter, and with some quick transfer paperwork and exchange of cash, walk out the door. The last shotgun I purchased took approximately 15 minutes start to finish.