If your wife likes photography, then your really do need to get the book I referenced earlier. Once you guys spend a few days flipping through it, you will have a better idea of where you want to go. Then get back on and ask about places to base camp from. I am not likely to be monitoring this threat then, but free to send me a PM if you are interested in one of the areas (just not in N. Parks...because we avoid them like the plague) that I referenced earlier.
Dogs can hike just fine too (unless they are really old). Some hikes are exposed (i.e.; risk of falling), so at a minimum you will want a leash along...besides being required by most agencies. Some of our hikes get a bit crazy so I usually bring a harness (for the dog) and length of rope (for all of us) along as well. The rock is abrasive so you may want to help your dogs out by conditioning their feet for a few months before going....by taking hikes. Once they experience plants with thorns, they will learn to stay clear. There are booties that may help, but they can effect the dog's ability to scramble up slickrock. A fabric water bowl (for the dogs) is easy to bring along and will help conserve water. Some hikes are even in the water for much of the distance so they will need to be comfortable swimmers.
Here is a
website you may want to explore. Likely you will be most interested in the "Family Fun" hikes listed.
I am already pouring over the maps myself, looking for a new place to explore this spring ourselves. There are many lifetimes worth of places to poke around in down there.
Just a word of caution. Hiking down there can be very remote and the environment is not forgiving of mistakes. And there is very limited cell service...and even if you manage to call for help, it could take many hours or days to get to you. So if you go off trail (pretty much anywhere besides in the Parks), you need to be prepared. If this is new to you, start slowly and work your way up as you learn.
Steve