Well, since these are meat birds, you might want to get males since they will be ready to butcher in 6/7 weeks while the girls will be a little slower. They cost more initially, but you save about a week in feed costs.

They will want to eat all the time... That does not mean you should feed them all the time. If they have feed all of the time, you will have lots of health problems. Try twice a day and only what they eat in fifteen minutes.
You might also want to try broiler booster from mcmurray hatchery. It is expensive, but I see a differance and won't raise broilers without it.