Pardon me for being biased but we have a suppressor manufacturer here in South Kakalaki that makes good stuff; here is a link to their rimfire page: http://innovativearms.com/index.html
I visited their store while I was passing by that part of the state. I brought my "suppressor host" (a Ruger .22-45 with threaded barrel) and was able to demo the rimfire suppressors. The owner also brought out a GSG 1911-22 which comes stock with a threaded barrel, all that is needed is an adaptor for the "can". The Ruger worked fine but the GSG was even quieter. The GSG is a pretty neat .22 pistol in its own right, but it's a crackerjack suppressor host.
By the way, another option for buying a suppressor is to set up a trust, which not only avoids the requirement for local law enforcement sign-off but also gives you more flexibility in regards to possession of the item. Spend the money to hire a lawyer experienced with NFA trusts to draw it up.