1979 K20... fix or replace cab?

[redneckchevy]

I got a 1979 K20 a couple months ago and really havent done much to it, but i starting looking at it lately to see what all i needed to do and thats when i seen just how much rust the cab has... most of the floor is rusted, were the bottom of the drivers door bolts to the cab it rusted out, cab corners are starting to rust ect So my Q is what would be the cheaper/ easyer way.
Should i just find a cab in good shape and put that on or should i try and replace the rusted metal in the cab?


Here is some photos of the truck
















The bed sides







Some of the specs on it are

1979 K20, 355 freshly rebuilt, 4 speed with GL, 9 inches of lift (all suspension lift), 37/12.5/16.5 OZ tires.



Whats do y'all think?