A booster is not a neccessity. It merely allows for the driver to use less effort when applying the brakes.
I built my old Ford '27 Roadster Pickup using a newer 'vette master cylinder without a booster, It is running front discs and rear drums.
The following link is to CH Topping Performance Brakes. This guy is an expert on all things brake related and my experience has been that he freely shares information.
http://www.chtopping.com/Home/index.htmlJohn