lowering suspension

[willie 64]

i picked up a new project . i still have another one i am trying to finish. it is 1964 c-20 very rusty truck my plan is to keep the cab and bed patina look. i want to lay it down on rockers i am going to channel the cab 4 inches. i am going to use a chassis from a1988 c-1500.my question is if i install air bags and dropped spindles will it get this truck low? also what should i use for the rear? i would like to take out the leaf springs.