>>64171416
Langdon kits are worth the squeeze if you want the absolute best but just the trigger bar and a 13-14 pound hammer spring is good enough.

>>64139017
92FS and M9 are what you want. They have remained largely unchanged since the 1980s.

>>63858583
.270 is the standard height, it’s what I used for these Novak sights on my compact

.290 is for Brigadiers/Vertec IIRC and .320 is for brigadiers/Elites with taller sights like the Elite. There’s a guide online if you google 92 sight heights