Pretty much all frozen pizzas are going to be bad for your child - sorry. Most of them have added sodium, fat and carbs that make them taste better, but in the end, they're really just not healthy.
I started my message before reading Dori W's, but I agree about pitas.
We started buying pita bread from a local Mediterranean restaurant, and we use it to make our own pizzas. because they're small, you can customize them for everyone. I like veggies, my kids (ages 2 and 4) like green peppers, mushrooms, broccoli and sausage, my husband is a meat guy.
A bad of 12 pitas costs us $2.50, we can keep them for a few weeks in the fridge. Contadina makes a squeezable pizza sauce that's good. Some shredded cheese and toppings in the oven for 8 minutes, and it's quicker than frozen.
I'm a working mom, so time is a huge consideration. And, having heart disease/diabetes on both sides of the family (plus being a cancer survivor myself), being healthy is huge for me as well.
Good luck.