Any 22lr silencer that can be taken apart for cleaning will work well. Prices are $100 to $400 or so. Here is a link to manufacturers; http://www.silencertests.com/links.htm
. The forum at SilencerTalk is a good place to learn more.
Check out http://www.gunbroker.com/Silencers-S...rearms/BI.aspx
for silencers on auction in your state. To buy from a person in your state, meet with the buyer and fill out the ATF form 4, get it signed by your local sheriff then send it in along with form 5330.20 two fingerprint cards two mugshots and a check for $200.
Making your own is easy if you know how to operate a lathe.
Any gunsmith can easily thread your barrel (10/22?) with 1/2-28 threads.