Rust repair, where would you start

[coggonobrien]

Going to start patching my 1969 blazer cst soon. Unfortunately it's a Missouri truck now living in Iowa so rust has gone wild. It needs pretty much every panel and I was just wondering if you guys would start with floor pans/rockers and everything that goes with them or new bedsides/floor. I have everything for the floor/rockers but just want to do it in the manner to get best panel alignment.

Thanks
David