Just as a different viewpoint, I would offer this input. I am a jig and fixture lover, so I might be more inclined to take a different look at this than some. I gathered two similar frames that were straight and used one to do all the chassis work and I made a roll around cart for the other one. By doing this, it was MUCH easier to do quality work on the frame without the body in the way, and I was able to do all the body and metal work, painting, etc. on the roll around cart saving a HUGE amount of time, as I was able to do frame and chassis work without the body being in the way, and do a much more detailed approach to the body without the frame being in the way, and I was able to avoid the preparation and 'un-prep' work and was able to continue working on the chassis while the body work was underway. I am absolutely convinced that the total time was noticeably less time consuming and I was happy with the results. I have done this on four occasions, with two projects ending up quite well.
Do what ever you think is best for you and your shop room and your fabricating skills.
HotRodAlley: That is very nice work you have done there, you can be proud! There are those of us that enjoy the journey as well as the destination, and I have learned over the years that if someone can't hear the music, they think the dancer is 'mad'.