As for body work and paint, considering I just did that on my 63 Riviera this year, here is what I know.
Labor: Well I would say I easily put in over 150-200 hrs of labor in body work over a 7 month period. One good thing (since I'm crap at body work) is the Riviera does not have a lot of curves (unlike a cobra, which is all curves).
Paint: I spent ~$900 in paint: sander/sealer, base coat, & clear coat at Mid-Nite Auto (their brand name), 1 gallon of each as I only needed the 1 gallon to put about 3-4 coats of each. The same setup in PPG was about $2400 at Mid-Nite. I also spent around another $200-300 in sand paper and misc supplies.
Granted, my intention was never to make a show car, but a nice paint job on a car I plan to drive a lot.
As for my Cobra, I took mine to Murrills Classic Dreams in Washington back in 2014. Paid, $7500 for door/hood/trunk gapping, body work and paint. He got it done in about 6 weeks, but again, it seems to be hit/miss with their schedule.