Here are a couple of good pages that should help you with suppressor ownership questions. It sounds more complex than it is and it is well worth it!!
http://www.advanced-armament.com/ownership.asp
http://www.srtarms.com/legalities.htm
Ar these the kind of home defense rifles you had in mind?
Silenced 44 Mag Rifle -- The Silent Destroyer by TD Mfg.
AAC M4-2000 Suppressor on AR-15