Now if I had this chance I would by it free and clear.
If the engine was toast, not a problem.
I would pull it into the garage, do a little research as to hp per vin and model year. I would rebuild it to like new specs. Tranny rebuild checking the ratio's and putting the more desire able ratio's.
Suspension, I love suspension work. I have not had a chance to work with carbon fiber unispring that is used on the 'Vette.
As a note I would use all GM parts as per year, make model and VIN.
I built a 1969 Mustang this way, I lft the 6cyl in but upgraded the suspension to the Gt, It wasn't hold your ass fast but in curves, full throttle. Brakes were from the list that was avilible per vin. I ended up with a 6cyl road racer when eveyone was building drag cars.
Sold it for way more then I had in it, after the buyer drove it.