Wheeler, the only gun that fits your parameters out of the box is the HK USP Compact Tactical. Dunno why you feel the need for a suppressor, as that complicates things tremendously.
I have a 1996-vintage P220 and a USP Compact. The USPc has it ALL over the P220 in terms of concealibility, in both size and weight, especially when you carry the USPc with the flat base magazine. Mag capacity is the same for both: eight rounds.
AFAIK, the only "smaller" version of the Sig .45 was the P245, now out of print. I have no experience with that one.
We have been dealing with Sig pistols since 1989; in typical German fashion, they have tended to remain the same without much innovation. Recently, that has changed, with the DAK (DA-only) trigger and a SA-only version of the P220. I haven't handled the latter, but the former is pretty miserable IMO. Sig has been trying to sell us on buying these to replace our conventional 220s; no sale so far, but the new FTU "person", who can tell a gun from a flashlight two out of three times on a good day, is nibbling.
Anyway... as you might have gathered from the responses, either pistol is great quality, but quite different in feel. You'll really have to handle them yourself to decide.
The price difference might be 2 or 3 hundred dollars in some yuppie gun store; but the pistols are comparatively priced in the real world. Both are expensive. Both are worth it.
Personally, I carry the P220 when wearing a uniform (rarely these days), and the USPc when in plainclothes (which is my usual attire). The reason for that is because I didn't see the need to purchase a $120+ uniform duty holster for the USPc when I have a perfectly good one issued to me along with the P220.
The Sig is a good pistol, and I will purchase my issued one when I retire here shortly. I would not hesitate to "take it into battle".
But the USP Compact is the one that stays with me constantly. Mine has the LEM trigger, which I feel is superior for close-range pistol fighting. And, IMO the HK is just on a higher level of quality overall.
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