Please note that I have not tried this, they are just some ideas that popped into my help:
Newly hatched crickets or pinheads should be small enough for young red eyes, I belive.
Now, I might be misstaken here, but bean beattles seem like a good choice. They are small and probably the easiest feeder to breed. They are excellent food for smaller lizards.
Before trying bettles, get someone to confirm or say against it, as I have not tried it myself.