You can fill these porta-pizzas with anything you like. I've included some suggestions in the recipe above, but feel free to think outside the box and use what sounds good to you!
One other option, which I didn't try this time but plan on doing next time, is to use a little of your favorite barbecue sauce in place of the marinara. Top with shredded chicken and sliced red onions, and you've got yourself a barbecue chicken pizza! If you want my favorite BBQ sauce recipe for this kind of pizza, you can find that here:
Barbecue Chicken Pizza With Homemade Sweet Baby Ray's Barbecue Sauce.