Well that's a million dollar question! What I would do is keep the Buick and buy a hotrod! Aside from that Its your car and you will be driving it so it doesn't matter what anyone else thinks. As far as actually building it as long as the quality of work is good it won't really hurt the value. Given the fact that stock type restorations bring good money compared to your average modified car, I wouldn't do anything you couldn't easily reverse. Have fun either way.