Ok, so I'm almost down to the shell, and the floors in my Z have been patched before with some pretty ugly welds so I'm going to do a floor replacement as many have. I've seen it done a bunch of ways and wanted to get some consensus if there is a better way than others. Right now the car is sitting un-sandblasted on the suspension and wheels. First question is it better to try and replace the pans while it's on the ground, on stands, or on the rotisserie (which I already have). Regardless of which one of those I get the idea of putting on the rear and front strut tower braces for rigidity as well as the trans support. Do I need to add additional internal bracing? Any guidance here would be greatly appreciated as always. Pics to come.

You can replace them with the car on the ground or on a rotisserie, rotisserie  is easier.  I like to leave the front support for the seats in place as well as the transmission mount.  Be sure to do just one side at a time.  When the car is a real piece of Swiss cheese then you may want to weld in some braces but lot of us have done the floors with no more bracing than the trans mount and it has worked out fine.  There are many threads with great pics of the floors being done if you're interested, the Build Thread in Chatter Box forum would be a good place to start.

Great, thanks @grannyknot!!