welcome to the site! Let us know your budget for the brakes. You can go as cheap as swapping stock later model GM disc brakes up front, to C5/6 Vette brake swaps, and all the way through the aftermarket stuff, tons of options.
Upgrading the brakes is a great idea. I had a 65 El Camino, and I remember the times that car wouldn't stop when driven "spiritedly".