If you are going to have 4 kids, a large SUV would be one way to go. You will have to use the third row seats OR have a bench up front and cram everyone in closely. The van might be a better choice.
I pulled my 21ft Starcraft hybrid with a Toyota 4Runner with the 4.8 V8. It did the job but one thing I did notice is the false impression that hybrids are more light weight than other standard trailers. My 21 would open up, had a slide out and felt much like a 25 ft. trailer, or maybe even larger. So, the weight of my 21ft was indeed less than a regular 25 or 26 ft. trailer. But light? Not really. Make sure you spec out the trailer and your choice of TV. And, camping as a family tradition can't be beat. You have many great experiences ahead. Your children will remember these years with fondness. Best wishes.