Take your pick.......I said screw it, and got all three.
The HK45 Tactical and the USP 45 Tactical are the quietest hosts......however, I like my FNX-45 the best tho.
HK45 Tactical - mags are fooking expensive! $70 each expensive. Comes with Meprolight night sights, but they can't see over the Osprey. Comes in 4 different colors. I got OD Green because I was tired of FDE. Doesn't come with thread protector.
USP 45 Tactical - best trigger of the three....9 pound DA pull, 3 pound SA pull. Buttery smooth. Sights see over the suppressor, but they're solid black. Would've been nice if they were 3-dot, but overall, the sights aren't that bad. Also doesn't come with thread protector.
FNX-45 Tactical - best value of all of these. Comes with three 15-round mags, soft case, suppressor height Trijicon night sights, and can mount a Trijicon RMR......basically, it's the ultimate tacticool gun, and makes Fudds scrunch their ugly little faces in disgust. Also makes anti-gunners cry.
Just my .02 cents of all of them.
FYI - try a 1911 suppressed before you drop money buying and fitting a threaded barrel......1911s usually make less than stellar hosts, compared to the polymer wonder pistols.....if you want a metal single stack .45 that suppresses really well, check out the SIG P220 Combat....also check out the new P227 Tactical.....has suppressor night sights.