Hi, Carl. The 19 is a great choice for a family of four. We've been fulltiming with our kiddos (4 and 6 years old) for some months now in our 17B, and we actually have a 19 on order as well.
You've outlined a good selection of options, and with respect to family camping in particular, I heartily agree with the front box, thermal package (works in hot or cold plus is sound insulator), outside shower and the cot selections.
Most other options are really a matter of personal preference, but one item of use that you might consider are some additional interior LED lights. We have extra fixtures at each end of the trailer plus one in the bath that we fitted with red LED's so anyone can turn on a light at night to see and get around without blinding everyone else. I especially like the "night light" in the loo. The red also preserves night vision. We did the retrofit in our 17B ourselves but are ordering extra fixtures on our 19 from the factory. We'll install the red LEDs after delivery.
Another area for consideration is shelving in the wardrobe. We find these to make our current wardrobe much more utilitarian and have same on order for our 19.
Along similar lines, we also pulled our microwave out of our 17B and use that cabinet as pantry space, and plan to do same on the 19, but we also ordered a shelf for the new trailer that will only be half the depth of the cabinet. This will allow two levels of shorter things along the back of the cabinet that can still be easily reached, and taller stuff can still fit as well.