Frame rack questions

[rlplive]

Ok guys. I know my car has been hit in the left 1/4 panel. The floor board is crinkled up, and the frame rail is definitely tweaked. The frame rail is also pretty rusted out. I am pretty sure it is going to need to be replaced. Here are my questions. Should I have the car put on a frame rack before I proceed with any metal replacement? I am planning on replacing the entire floor pan first. My other questions is this. When do you replace the frame rail? Do I need to replace the floor and trunk pans before I replace the frame rail so I have something good to weld it to?

I am a novice at this, although I am planning on trying most of this stuff myself. I have a hobart welder and a lot of courage. thanks
Ryan