Intake manifold and carb?
 

What;s the best for a 12a?

Loaded question. What are your goals, usage, purpose for the car? Need more info.

well my overall goal is 50 + hp but doubt i can achive this through those alone.

You can get close to that, if you do exhaust first. Stock 12A, look for a Weber 45, Mikuni 44/48PHH. Some like the RB Holley setup. Carb upgrade will be of little benefit without exhaust, that's where most of the easy power comes from.

I did the exhaust last year. Pace setter header, no cats, a louvered resonator and a dyno max muffler. I don't know what's good so i just stuck it on.