Most people don't use a carrying handle anymore. Back up sights can be fixed or flip up. Whether or not it bothers you to see a fixed front sight when using a red dot is up to you. Personally, I have a fixed front sight but I don't notice it because it's set up for a lower 1/3 cowitness (there are other threads here about that).
Go here and look at the pics of the many different ways how people set up their rifles. That will give you some ideas until you decide what you want.
http://www.ar15.com/forums/topic.htm...f=118&t=510264