If it looks like the one pictured here; http://www.proxibid.com/AuctionImage...tail/41004.jpg
then it should have ample room for muzzle threads without cutting or setting the sight back.
There is a decent sticky post here; http://www.thefirearmsforum.com/showthread.php?t=73885
about owning silencers and other NFA weapons.
You can find a link to manufacturers here; http://www.silencertests.com/lnks.htm
. The SilencerTalk forum and Subguns forums are good places for advice. I have made a few silencers on ATF form 1's (223, 22lr, 44 mag) but know little about the professionally made ones except to say that I was impressed with the noise reduction of AAC and Gemtech models.
What state are you in? You need to live in one of the 38 states that allow civilians to own them, but the application process is easy and routine, even if it takes a few months for approval. I've heard that the ATF never denies approval to anyone was long as they fill out the application properly. You can download the ATF form 4 from www.atf.gov
but the fingerprint cards have to be ordered from them via the mail or obtained from another source.
As far as I know, a gunsmith can work on your title 1 rifle without you being present. Unless you have a lathe or know how to use and have access to one, then you are better off getting a gunsmith to put threads on it. You can find instructions for threading here; http://www.silencertalk.com/forum/vi...hp?f=10&t=6773
if your gunsmith needs them. Trying to cut threads on a muzzle with a hand held die is not likely to work, the threads will be crooked. The silencer has to be well aligned to the bore to prevent baffles strikes which will ruin accuracy or destroy the silencer.
Most 22lr silencers are about 1x6 inches and made from aluminum unless they are intended for machine guns. Prices will vary from $150 to $500 for most plus the $200 tax stamp. I think silencers are well worth the price as they make it much more fun to shoot in my opinion. The 22lr is such a low powered round that even the cheapest silencer will make your rifle safe to shoot without hearing protection even with supersonic ammo.
I do not know if a silencer will aid you in hunting though. While I have heard that the suppressed high velocity rounds might confuse the prey as far as shooter location is concerned, the prairie dogs will probably learn to associate the bullet flight noise and impact with you and be just as elusive to shoot as before.