I owned an H&K USP Tactical in .45ACP. I notice that your choices are of the H & K brand, so I feel I should caution you just a bit.
H & K has a mystique about them - they are in every video game, every movie and they know it. Their customer service is not the best and their service after the sale is lacking. Keep that in mind before you spend some hard earned cash.
Now, as for the weapon itself. My Tactical came rated to handle +P loads from H & K, which is something that a lot of manufacturers won't do without changes to their product like a recoil spring, and even then it will compromise your warranty. I had put about 1,000 rounds through it and never had any problems. It came with adjustable sights, which I personally find useless on a pistol, I prefer fixed night sights. What good is adjusting for a wind variable that is only present on one day shooting?
The pistol is big, almost too big and this is from a design that was "downsized" from the MK-23. I am over 6ft, wear XL gloves and even my hands are "too small" for this weapon to be handled properly in my opinion. To eject the magazine, I need to either use my off hand thumb, or rotate the weapon off target to press the latch that drops the magazine. While not a big deal, I feel that it's inconvenient and not the safest of actions to give up that firm handshake on the butt of the weapon just to replace mags. The trigger pull is good, with almost zero over travel right from the factory, but once again it's not a 1911, so it lacks in my opinion.
This is not a carry weapon, unless "carry" is on your hip, in a tactical thigh rig. The weapon weighs almost 2 pounds unloaded and that is a lot of weight to pack around all day on your hip or in a shoulder rig. Plus the profile is huge, so unless you are "working" in a ski town with a lot of heavy layers, or you are a member of the trench coat set, this will stick out like a sore thumb.
You can carry in position 1 with this weapon, which is a plus in my book. The frame mounted safety is one of two and is crisp with a positive "on" & "off".
As a home defense pistol, in a safebox next to the bed, it's a great piece of kit. 12 rounds of +P will put anyone in line for a dirt nap, plus it has in integral frame rail to put a SureFire X-200 to light up the night.
For a carry gun, I would recommend you look elsewhere. For a good home gun this pistol has several pluses that make it cool to own and it always garners attention when you break it out at the range. Comes with ( 2 ) 12 round mags, several replacement rubber "O" rings for the barrel and a neat black, tactical nylon carrying case.
Best of luck in your shopping efforts.
PS - As for .45 or .40
I carried a .40 for several years and like the round. It has good power, it's common, but it is a bit snappy in feel on recoil, especially in a poly or aluminum framed gun. Lots of muzzle flip in your average pistol.
The .45ACP, in my opinion, is just a better all around cartridge. Given the platform that you are looking at though, the .40S&W is going to offer a lighter and easier to carry weapon.