I ordered ameriglo n/s for my 9mm sc. They were sent to a gunsmith for installation. I would NOT reocommend them!! The rear sights were supposed to be yellow and front sight green.
After getting the gun back, I had meprolights installed to replace the weak ameriglos. The meprolights, though more expensive, are clear to pick up in fading light and in condiltions without light. On the other hand, the ameriglos could not be seen in fading light and, only with prolonged study of the sight, could I see the faint yellow rears and faint front green.
On my Sigs, I have trijicon (P232 factory n/s and P225 after market trigicon n/s); and they work just fine.
I would buy n/s at a gun shop where they can be installed, so you can check them to your satisfaction. I had sent my slide away and had two bad experiences.