I think you need to provide a little more information before we can give you any good suggestions. What is your main purpose for this gun and what is your budget?
Just because all of your other guns are 1911s doesn't mean you have to stick with 1911s (unless you plan on carrying this gun). A strong case can be made for muscle memory and familiarity with the 1911 platform. If not then that open up a whole lot of possibilities. I don't have any experience with any of STI's 9mms, but I do have the STI Edge in .40 S&W and am very impressed with it.
The brands you listed make great guns. While most people have commented on the P228 or P229 from Sig or the USP or P30 from H&K, Only one other person has mentioned the Sig P210. The P210 is definitely NOT cheap, but it is one of the most accurate 9mms you will ever shoot. Sig re-released the P210 and resolved some of the "issues" people had with the previous version. Those changes include an extended beaver tail to avoid hammer bite and switching the mag release to the American Style thumb mag release rather than the European style heel release. As for H&K, the P7M8 is an incredible pistol as well. It is one of the most accurate compact 9mms I have ever shot and the trigger is as good as any 1911. If you are looking to save some money, you could always go with the PSP model which is very similar to the P7M8.
If your budget is not that high, I suggest you look at the Browning High Power which is very similar to the 1911. It lacks the grip safety, but is otherwise almost the same. I also suggest you consider Glock if you are considering a carry gun. I used to be a Sig snob, but I switched to a Glock 26 as my carry gun due to the smaller size and consistent trigger pull. I then switched to a Kahr PM9 which is even smaller.
I own a variety of guns and I like having different types of guns to shoot. The 1911 is a great platform, but why limit yourself. Here is a list of what I own so you can see the variety.
.22 LR Browning Buck Mark (Standard but swapped to the 5.5" full Bull Barrel)
.32 Beretta Tom Cat (pocket gun)
.357 Ruger GP 100 (6" Stainless)
9mm Glock 26
9mm Kahr PM9
9mm Kahr MK9 (weighed so dang much I bought the PM9)
9mm H&K P7M8
9mm Sig P210-6 (I couldn't bring myself to shoot the 50th Anniversary Edition)
9mm Sig P210 (50th Anniversary Edition)
.40 S&W Sig P229
.40 S&W STI Edge
.45 Les Baer Thunder Ranch Special
.223 Colt AR-15 HBAR
.223 Smith and Wesson M&P Sport
30-06 Sako 75 Synthetic
12 GA Remington 870 Marine Coat 20"
12 GA Beretta A400 Unico Synthetic
The ATF should be a convenience store instead of a government agency!