The whites are males and I'd say they are 7-8 weeks old at the least in order for the males to be white. They tend to get more of a pure white as they get older.
They may never say a word until you split some of the males up, none of mine did. I take a male and a couple females and put them in a seperate pen out of the site of the others in the spring and they'll start talking alot.
As for the feed............look here:
http://www.thatquailplace.com/smf/index.php?topic=164.0