sig makes a 1911 with threaded barrel and rail msrp 1285$. its called tacops. there are two versions of it with and without threaded barrel. i cant speak for the quality and reliabilty of sig 1911's as ive never even held a sample.
i assume you want a threaded barrel for a silencer. if that is the cse i would totally skip the 9mm as you have to use special underpowered subsnic ammo to get rid of the sonic crack. if you just want to reduce the report and dont care about the sonic boom then it doesnt matter so much.
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith
The problem with being stupid is you cannot simply decide to stop doing dumb things...
"I crapped my pants to avoid the draft!!" -Ted Nugent