I would say if you have the money go for the LR3, if not, an 04 D2 would be the best bet out of those choices. The question is, with you, your wife, three kids and a dog, is even an LR3 enough space? Because if you fill it up with gear, and all the seats with kids, no room for the dog. I have seen on this forum that once you reach into the three kid range you have to start looking for something with another row, such a suburban or the like. You can even get them in the same vintage as these LR's. They are easy to find parts for in the US, and hell get about the same gas mileage. I would look into something bigger if I were you.
'98 Land Rover Disco 1 - BFG AT/KO