I haven't found a picture showing the difference between male and female yet, hopefully when my new book comes I will be able to find something. I would suggest getting all females if you can help it. Though, I don't think LA allows you to pick gender...
You will be lucky if you can get carberryi down to two feedings per day. I know people are able to feed lyretails less than other anthias. My suggestion is that you start with a lot of feedings and slowly decreasing over time. While decreasing keep an eye on the anthias to make sure they are getting skinny are staying fat and happy.