Dubia beetles are fairly easy to keep. Here is my suggestion. Get a few dozen adults. Mostly females with a ratio of 4 or 5 to every male is probably best but not really that important. The males won't fight or anything if you have a higher ratio. And also, get a few hundred babies.. For the simple fact that you will want to feed you lizards some dubia while you waiting the 6 months for your colony to establish.
Here are my tips from keeping a colony for a while with no crashes, diseases, or problems..
For water, get terra cotta pot bases / drainage saucers.
Just fill them with something like soilmoist soaked in water.. The little granules of Crosslinked polyacrylamide will soak up a ton of water.
The gel will hydrate the beetles and keep the enclosure humid. The terra cotta pot base will also absorb some of the moisture and help keep the enclosure humid as well. In a year with several thousand beetles I still haven't used half a bag of $7 worth of soilmoist.... Works great.
For food, just get really high quality dry ingredients. Put it in a blender to turn it to dust.. I think my food is half dog food (As stated below dog food is not for chameleons.), oats, dry kelp flake, fish food, and a sprinkle of NatuRose powder. (NatuRose is pure Astaxanthin antoxidant).. But in reality you can really make any food mix.. I stick with dry food to avoid fungus issues.. I'll watch what they pick out of the mix and alter the next batch of food accordingly. Make sure it is ground up though as they seen to have a hard time food in large hard clumps. I noticed a large difference in the amount they eat once I put my food in a blender.
Heat can be provided in many ways as long as it's in the high 80's to low 90's.
Here is my setup. That small box in the middle was for a select group of breeding females and males and maintained a different temperature than the colony. It has since proven unnecessary and has been removed..
Cleaning the cage can be done pretty infrequently as the smaller beetles benefit from stuff dropped on the enclosure floor.. If the cage smells, it needs cleaned. That's about it.