Well, it would seem silly for me to simply to respond with 'ALOT!!!' so I will try to answer the best I can with how I do things.
To start, for neonates I feed almost exclusively Hydei FF. This is for a couple of main reasons.
1. Costs, I can make FF cultures all day long until the cows come home for nearly nothing. So when you NEED food and cant worry about cricket production, FF are great.
2. I keep the neonates in tubs with screen bottoms to let the water drain out. The pin heads can get through the screen. The FF can, but they tend to crawl around foliage and sides of tubs mainly.
I raise Crickets, I rather I use to, Ill get to that in a sec. But when breeding crickets I was producing about 10,000 a week and that was not always enough.
Now, Ghanns, who is a sponsor here, has their Breeders program. It is an AMAZING deal for those that need lots of food. For example, I just bought 20,000 1/16" for a GREAT deal. Good enough that I stopped raising crickets!!
I would suggest you reach out to them and see about getting signed up if you are going to raise that many babies.
Again though, start with FF for the first few weeks at least, then move to a mix of the two, then once they get some size to them, you can escalate the cricket size as well as introduce dubia nymphs, etc...
I will tell you a secret that is not such a secret really. If you are looking to sell these babies, and I assume you are with that many, your ability to make money or just break even is all in the feeding of the babies. They will literally eat you out of house and home if you dont have a plan.
HTH,