The carry handle can easily be mounted once the riser blocks have been removed.
A Williams Fire Sight replaces the front sight post in a forged front sight base and clamps to the front of the sight base. Sight bases and or gas blocks that are attached with taper pins are not interchangeable.
In order to mount those flip up sights the flash suppressor and gas block need to be removed. The gas block has taper pins that come out left to right or towards the ejection port side. The flash suppressor crush washer will need to be replaced as they should not be reused once they have been crushed.
Another front sight option is a V-Match flip up sight that clamps around the existing gas block so no gunsmithing is required.
The Trijicon sights can be installed in those front sights.