Welcome! Given your recent entry into this lifestyle, I would say a good shop will be very valuable to you as you test ride different bikes to see what you like. I agree that, at $600, most hybrids will more or less have the same or similar components and same or similar capabilities. It just depends on what your body finds comfortable. Trek makes great bikes, but other brands do, too. I would give both shops a visit. At Trek, the three models that will most likely appeal to you are the Dual Sport, the Verve, and the FX. A test ride will probably tell you pretty quickly which one of these three you like the best. And maybe you like one model and your wife likes another model.
The independent dealer would be good to visit, too. Most bike brands have bikes similar to the Dual Sport, the Verve, and the FX. But they'll feel different -- they'll have slightly different geometries and dimensions and things like that. Small differences in ergonomics can make a real difference in your riding comfort. Because they have different brands, and hopefully some good selection, you may be able to test ride a number of bikes in the same category to see if one suits you better than others.