Then I saw this mix (on sale at that) and it looked perfect! It's a freeze-dried mix of river shrimp, mealworms, and crickets - nothing else added. All small-sized and well mixed. It cost just a little more than 6 bucks, and I thought it would be a good way to figure out what they'll like.
58% Protein, 12% Fat, 10% Ash, 8.75% Moisture, 7% Fiber, 2.75% Phosphate, and 1.75% Calcium.
I just added it to both tanks, and I'm hoping they'll pig out overnight.

Surprisingly it doesn't smell bad. I really thought it would stink since it's dried bugs, but it smells exactly like KMR. (It's a brand of powdered kitten formula.) It smells like protein-y powdered milk.