alot of vague answers.
Legal - YES/NO depending on where you live.
Affordable?? - YES requires a one time "tax" of $200 per item . This is in addition to the cost of the unit itself.
You are talking about a MKi,MKii,MKiii pistol??
There are 2 options
(1) You must use a BULL barrel model. They can move the front sight back, turn the barrel down and thread it. ($125 or so)
(2) Buy a tactical solutions PAC-LITE reciever/barrel assembly ($200)
As for silencers go, I went with a SWR WARLOCK. They run around $300. Then you have to pay the "TAX" so that brings the total to $500.
As for pistols go, I have a WALTHER p22. You can buy a adaptor for $30 and be good to go with it.
I haven't gotten my suppressor yet (be another month), and I am about to send my Ruger off to get done. I am also getting my Beretta m21 pocket pistol threaded.