Yes, your challenger is awesome!

For originality purposes the delstar is probably going to lay down and provide a more correct shine than any urethane paint. It's good paint, but with so many people using base clear it seems out of the ordinary, kinda like chevy guys repainting their 60's vettes with lacquer. It still happens, but not nearly as often anymore.

It's still available here, but the paint store people will go out of their way to sell you something newer (and more expensive). I have 2 quarts of black and a quart of clear that I use for detail work. My dad had his 64 nova painted in delstar in the early 90's and it's still holding up great.