Upgrading BRAKES >_<

I HAVE a 1968 Barracuda power brakes. motor (1973 dodge charger 440 magnum)

8 3/4 rear on drums

73+A body font disc's

front and back big bold patter.

stock power booster and master cylinder.

As of now it stops slowly if pressed hard.
I want to stop on a dime or as close to it as possible.

not much to spend, so what would be the next best thing to make this thing stop a bit better?

upgrade booster?
upgrade master cylinder?'
upgrade to aluminum slotted/drilled rotors?

if so, can anyone refer to any or the proper equipment? :cheers:

thanks.