You've made a sound choice based on your critical needs. Everything else can be adjusted to those basics.
So far as storage, you will be fine. Like someone else said, make every kitchen item serve multiple purposes. With a family of 4, you need one pot and one skillet big enough to cook a simple meal. It's a huge help to make freezer meals and bring them along---spaghetti sauce, vegetable soup, beef stew, casseroles, etc. Plan the rest of your meals to be simple so you don't need a big assortment of kitchen tools. A colander for pasta, a couple of good knives, a cutting board, a can opener, and a couple of cooking spoons should be about all you need.
So far as clothes, a couple of things are a huge help. Packing cubes or the 2-gallon size of ziploc bags are a great way for kids to keep their clothes organized. Invest in some fast-drying items so things can be rinsed out and worn multiple times---polyester fleece, moisture wicking shirts & pants, things like that.
Give each child a backpack or shopping bag to keep their "toys" in--electronics plus chargers, games, favorite stuffed animals.
You also need to keep the interior uncluttered so you can be ready to move out without a lot of preparation. Don't plan on leaving items sitting on the table or countertops, they will slide off.
When the kids get too big for the bunk or dinette, they can move to sleeping in a tent out back. You will see LOTS of families doing this. It gives everyone a break!