Newbie- want to feed + breed dubias

[midwestmom]

Hi! We will have our dragon in less than a week and more and more I'm realizing I will not be a fan of crickets and would like to primarily feed dubia.
Our dragon is around 6 inches (maybe bigger)
I would like to start a dubia colony as well as have dubia to start feeding from

Where do you like to order from?

What should I order/starter colony- how many breeding females/males as well as how many younger roaches to start colony?
What size dubia is appropriate for 6—7 inch juvy? How many of those would I order to feed from until I can feed from my colony?

Thank you for your thoughts!

Midwestmom