Is there something like Requiem for this?
It depends on what you like about Requiem:
- If you want a more traditional RPG, then you should try
Cirosans Classic Overhaul. Does what it says on the tin, making New Vegas feel like more traditional Fallouts when it comes to S.P.E.C.I.A.L. and other things. A compact mod overall.
- If you want a more hardcore "die all the time" experience, you should play with V
icious Wastes. It's a very good mod that makes tons of tweaks into the game. It's a shame that it's so hardcore you die way too often, to the point Fallout 4's "survival" runs would be impossible since you would die 1 out of 2 times you face enemies. Plus the few times you don't die, you mostly come out unscathed of fights. It's got a very detailed changes lists, so I sugget you read it.
I would recommend Cirosans Classic Overhaul personally, since Vicious Wastes makes the game drag on for too long since making money is particularly hard and carry weight is fairly low (you've got Relaxed, which gives you 150 tops with 10 Strength, or Strict, which gives you 100 with 10 Strength IIRC).
EDIT: I need to clarify. Vicious Wastes is not meant to be a "die all the time" mod, but it just ends up being that way because we are dealing with bullets, not with swords and bows or crossbows. Requiem too would be that way if enemies had assault rifles instead of bows that take time to fire and can be easily dodged. Sadly, EVERYTHING good that Vicious Wastes does (which is, to be honest, a lot) is sort of hampered by how quickly you and everyone else dies, product of the low Endurance values.