I want to make a evil instatute character but I can decide their build. I'm thinking either a big guns power armor character or a stealth character

Problem with a big guns character is ammo since weapons like the minigun use alot of ammo which is very expensive. I could use the junk jet but that is quite clunky and buggy.

Problem with a stealth Character is that I don't really know how to use stealth in fallout to be honest it sounds very complicated. And if I make a single mistake I wonder up dead. Plus how do I deal with groups of enemies.

Another problem is leveling up on my other characters I used endless quest lines such as helping put settlements with the minute men. But I only want to help the instatute so how would I level up my character and gain perks.

Lastly what special stats should I set up for my character in order to get the perks I'm going to need as early as possible and what perks should I egy in what order.