As far as one ship vs the other goes, NH is the best ship, it is a fully fledged CA with the range and damage of one.
However, chance are since you are probably new to the game, you will be unable to use the ship to its full potential, and yes, it requires better gunner than the brooklyn to work decently (if your gunners aren't BVE, you'll hate the spread).
Brooklyn, should everyone be good at playing their CL, would easily be the worse CL2 out there, and be a glorified DD killer and CL1 killer (then again not all of them).
But its not the case, and the brooklyn shines at making people pay dearly for their mistakes. And blitz is full of mistakes. See where I'm going? It shines.
But mostly, you'll want to ask what BB line you are taking. Both have very decent ship, and less decent one. USN BB2s are the same pretty much, with slight advantage imo to the colo vs the tenn (thats debatable tough, due to better firing arc on the tenn), but the BB1 and BB3 are not the same style at all.
Nevada and pre-BB2 tenn/penn is built for hard salvo, but with low speed. Alaska/Guam is an agile BC, that is built to pursue its target. Any non-experimented BB player with any of the two ship is going to get pwned most likely in GB. Nevada is a bit easier to use imo, due to the angles. (30 vs 45)
Now in my opinion the kicker is at the BB3. North Carolina at level has horrible spread, and is way slower than the sodak for a bit more range. The damage is noticably higher, but good luck landing a full salvo. I got both lines, and my level 120 gunners struggle to do it. The sodak continues in the Guam line of a very fast and agile pursuer, with slightly better spread and good damage. I always had a soft spot for the ship.
Another reason you should look at the BB3 first is that it is going to be a ship you'll spend a lot more time in than the CL/CA. (normally its BB2/BB3 you look at, but since BB2 are quite the same...)
So should you choose only one BB line, I'd say go brooklyn.
However, I encourage you to use the dual BO leveling (1 BB crew, 2 BB BO) that allows you to keep support at level, gunners ahead, and give you a taste of all of the BBs USN has to offer.
Also, you'll love having gunners ahead in the USN BBs. Spread at level tends to be meh.