I looked into starting a build with a salvage title JKU. I talked to a guy in Phoenix whose business was buying salvage cars (small sedans, mostly Ford, Hyundai, or KIA involved in heavy corner collisions with less than 5000 miles on them.) His advice was "If you know what you're doing from the rebuild to the paperwork, you may come out ahead. However, experts even get burned from time to time." He was an artist and the process was quite impressive.
The most surprising thing I learned was that a majority of these "salvage" cars change hands two or three times before they're even fixed or parted. By the time it gets to you there's not much meat on the bone.