I'm going to be ordering my first roaches next week and trying to find out what to order? I have 3 18 gallon bins to use for colonies. Whats to best number to start off with? Do I order mixed groups or just med-large sized? Whats a good number to start of with for each bin? I came across one site that sells 420 mixed with 8 adult females and 5 adult males? I'm not sure which way to go starting out??? Any help will be great, thanks!