Floor pan and quarter patch help needed.

I plan on replacing the entire floor pan. It's not all destroyed by rust but I figure just do the full pan that way there's no worries about the areas that are slightly questionable. I have not removed it yet though as I wanted to order and have the new one in hand before going crazy. It looks like there are a crap load of spot welds holding it in. I was wondering if while it is removes if the lower door sills require ratchet straps to prevent body twist or if it's going to be just fine as removed. Can I have her up on jack stands during this process or will that come in to factor as well? Thanks alot