I've got a Springfield Armory Mil-Spec. I really like it. It's completely adequate for your purposes. The biggest difference in them is just the feel of the gun in your hand, so the Loaded may well be worth it. From the perspective of the grip alone, the Loaded model has a beavertail grip safety, a flat main spring housing, and a long trigger. The Mil-Spec has a normal GI style grip safety, an arched main spring housing, and a short trigger. You'll have to see which you prefer. I like the Mil-Spec layout myself. Functionally, some people say the flat main spring housing makes the gun shoot a little lower, but I personally believe that's more for snap shooting without a sight picture, and it could be a good thing if you tend to shoot high with the arched housing. Both have fully adequate sights, the Loaded ones are less likely to snag if you go with the low-profile sights. I tend to find the simpler sights such as those on the Mil-Spec to be a little more precise for me.
Ultimately, if you are comfortable with the set-up of your Parked gun, I'd get whichever one mimic's its setup and has the same feel.
