Installing new quarter panels

[scherp69]

I'm in the process of replacing the quarter panels on my car. I was told by some people that the car needs to be supported at the front and the back. It was recently suggested to me that I should have supports in the middle of the car also. I've attached some photos to show how I have my car sitting right now. Will this work while putting new quarters on? Also, there's a photo that shows the set up that was suggested to me. Which is the right way? The other option I have is to put the suspension and rear end in and install them while on the ground. Which is the best route to go??? Any advice would be greatly appreciated as I only feel like doing this once. Thanks in advance.