They and Wilwood are premiere brakes designed for serious racing. If you are thinking of racing that is what I would buy.
If you are not racing then your drum brakes will work just fine: once. The heat that an emergency stop creates from seventy miles an hour or above will heat check the drums as they were designed to stop your car from only 45 to 50 mph. If you are not over working the brakes then they will last for another fifty years (assuming you can find parts).
Brakes are sized by the weight of the vehicle (why semi trucks have drum brakes that have four inch wide shoes in a foot and a half diameter drum). So if you want a heavier duty brake look to a heavier vehicle (police cars used the brakes off of a half ton pick-up truck that when fully loaded weighed nearly twice the weight of the police car). Those police car brakes are still available as a service part or from a junk yard.
The other factor that affects brakes is in how fast you are trying to stop the car from. For this reason Corvette brakes have gotten bigger and bigger as the top speed of the car has been climbing annually to near 200 mph. Funny thing is the full sized cars had C3 Corvette brakes as an option in 1967-'70. They still bolt up but will require a 15 inch wheel to clear the Girling fixed bridge four piston calipers.