I have a G36 with the stock sights. I plan to put on some night sights for both carry and IDPA. I am looking at the heinie straight 8 and the Ameriglo I-dot. How do they change the sight picture and POI, 6oclock etc. Also I have a Serpa holster and will be getting a Concealment solutions holster. Do these sights cause a problem with these holsters?