I know many bunkhouse TT's have the outside kitchen, but take a close look and be sure it is what you would actually use. I have looked at some trailers, that if the lot had any slant, I was too short to use it much. some have poor stoves, and some have grill connections, some only have sink and elec fridge and some don't have a sink. Look carefully and think about how you cook outside when camping now. Since I came to the TT world from tent camping, I already had a good stove and a kitchen table that I love, so I didn't consider an outside kitchen. I set up just outside of my awning, and don't have to work about heat/grease near trailer (and I can put up a canopy over it if weather threatens) I don't have kids drinking sodas, so the outside fridge wasn't that big of a deal. My cooler works well (when I need more space than fridge). Also with 3 kids, you may find you need the storage more than you need the kitchen.
Not trying to change your mind, just make you think if the idea of an outside kitchen is cooler than the actual kitchen design will be in use.