Hi! I would recommend the kritter keeper first, then the 10 gallon later. This is to avoid stressing your frog. Another thing you can do to reduce the risk of stress is cover the back and sides of the container. As for food, nightcrawlers are a great food, as are roaches, and they even make pellet foods for Pacman frogs. Some people really like them, especially those who don't like bugs,but these must be fed from tongs, as frogs generally hunt by movement. Superworms shouldn't be fed too often though, as they are high in fat compared to roaches and crickets, and contain a lot of chitin/shell. They're okay, but not a "healthy" food.
Also, I meant to include this, but forgot:
https://www.caudata.org/cc/articles/foods2.shtml
It's a pretty useful link.