Won't this question ever die? Seems like every couple of months it is posted.
Besides being extremely expensive there are two other issues: (a) the VIN will no longer match what it is and (b) your collision coverage could be terminated. Why you may ask? Performing a "re-engineering" no matter how much quality will become a major issue with your insurance carrier as well as bank. If you are ever in an accident with such a car and an adjuster views the auto, the "re-engineering" will be noticed. The adjuster may (rightly or wrongly) decide that the accident was caused by the "re-engineering" and cancel your policy on sight, making you solely responsible. Same for the bank which will probably call in the loan as the value of the "re-engineered" auto is only worth parts. The bank may also begin to speak about Fraud. The last question to ask yourself is whether "in your heart of hearts" you would ever buy such a "re-engineered" vehicle.
If you don't believe what I have written, contact your insurance provider and bank. Then post what you have determined so that this question may finally die a respectful death.
Why would you wish to assume such headache and responsibility? Just spend some time and find a manual car even if you have to refresh engine, trans, suspension, etc.
During the 8 yrs I was working in autobody, I did my share of sectioning and frame replacements. I would not touch this kind of project due to the myrid problems inherent in its attempt. It would be easier to section two wrecks.