As far as Glock Gen 4 and Gen 5 night sights you can use Gen 5 sights on a previous Generation Glock pistol in 9, 40 & 357. The front sights are the same height 4.1 mm. The Gen 1-4 comes with a 6.5 mm rear sight height. The Gen 5 rear sight is 6.1 mm but the notch is a little wider. I put Gen 5 factory night sights on my Gen 3 Glock 23. I guess I’m not a good enough to tell but my pistols with 6.5 mm rear sight seem to shoot point of aim and so do my Gen 5 6.1 mm rear sight pistols.
You can buy Glock factory green tritium night sights from GT Distributors for $57. These sights are not individually packaged but GT gets them in bulk. I’ve bought several sets.
Here is a picture of my Advantage Arms 19/23 LE kit with Glock 6.5 mm rear and 4.1 mm front Tritium night sights.
Here is a picture of my Glock 44 with 6.1 mm Gen 5 pattern front and rear tritium night sights. Notice the front sight on the Glock 44 has a different profile than the earlier front pattern sight.
Gloch 19.5 front night sight 4.1 mm
https://www.gtdist.com/glock-screw-on-front-night-sight-g17-gen5-g19-gen5-g26-gen5-g34-gen5mos.html
Rear 19.5 night sight 6.1 mm
https://www.gtdist.com/glock-rear-night-sight-gms-for-gen-5-model-17-19.html