Which holster and light to get for the FN Five-seveN?

Hello, I am torn between an Surefire x400 and the viridian x5hl and which holster would fit the Five-seveN with the light attached. Also, would I have to replace the sights and use night sights also? And how much do you think total would cost after all is said and done. Looking for some opinions. via /r/CCW http://ift.tt/2vL0zFg