Firstly use this and plan out your build. You can respect ability points once per playthrough and for a high cost at that. Perk points can be swapped around anytime which allows for some flexibility.
https://www.cyberpunk.net/en/build-planner
Secondly YouTube is your friend - it’s flooded with so much good content on builds.
Finally the rule is that you can max out three ability trees, the fourth can go up to the 18 (that too very late game) and you’re best leaving the last one alone.
So you have to see what sort of stealth you’re up for - hacking / pistol (the only type of gun with a silencer mod) / throwable knives. I will be playing something like this in my next play though so I’d probably go with
- Intelligence (to get all the netrunning / hacking perks)
- Refexes (to allow for movement and blades perks because they’re just so much fun)
- Technical ability (because it just allows you to go bigger with cyberware and again, that blends well with net running and is just fun to have the option to do)
- Cool - while this is really want you want for a pure pistol stealth build, for me it doesn’t add fun factor and more than build a specific build, I want my build to be fun.
And on that last note, personally I’d focus on your personal preference as well as fun factor. Try to go with a build that lets you explore a couple of ways to play as that’s the magic of the game’s systems - to be able to switch between weapons, cyberware and play styles mid playthrough to keep things fresh.