I'm looking for iron sights for a Glock 40. It is going to be a hunting and long range (out to 100 yards) pistol, so I want to get sights that are good for distance. I have seen trijicon hd xr, I like them but can not find them in stock. Will I need to get different sight dimensions than I would for a Glock 20 because the slide is longer ?. What iron sights will be good for hunting and distance shooting ?