This may seem very callous on the surface, I assure you that I don't mean it that way.
What he wants may not be what he can get.
There are a number of good quality fixed sights on the market. Most of them have a propietary dovetail cut size. I say that they are easily changed because the one wo does this for mine seems to have no problems.
I suspect that he wants too save money, and, in these times that is a very good thought, however; it may not be possible.
You just need to check the size of the dovetail and look around. Most will take some fitting, I suspect.
Blessings