Well, depending on the extent of the cancer, i'd say start with the floorpans. Do the rockers when it's a nice warm day with plenty of sunshine. Floorpans are just a matter of "out with the old, in with the new". Rockers require a lot of patience to line everything up with the cab, doors, etc. Pick a good day that you feel good waking up to, make sure the weather is good for about 4 hours, and break out the grinder, torch, and welder. Good luck, I know I had fun doing just the driver side on my 77c10.
-Mike