Did you add a power booster to this car? Or did it come factory with power brakes. If you added it, you need to change the pedal to a power brake pedal in the 70. THe geometry is wrong for power brakes with a non power pedal. Makes them really touchy. Try is with discs...even worse.
Yes, the disc brakes will feel more like a modern car. I have heard that using a late model booster also helps to give a more modern car type pedal feel.