Brakes

On my 99 Express with auto and 4.3L V6, The brakes don't seem to stop well when the pedal is first pressed. After a second or 2, they do much better. The rear has been overhauled by Goodyear, drums, lining, cyllinders etc. The fronts have new ceramic pads on the unturned stock rotors. I see several drilled and slotted rotors available. Will these help the braking, or just accellerate pad wear?

Check the rear brake adjustment. Improperly adjusted brakes will give the feel of a low pedal and force even more braking on the fronts.
Drilled and slotted rotors are primarily designed for cooling purposes and will not really help your situation.