Check out the Protouring forums to see all sorts of cars with just what you are talking about. You have to wade through a sea of 67-69 Camaros, but there are a good number of Mopars there too.
Do yourself a favor and test drive a new Corvette. It is a ridiculously capable car for the money. I'm not saying that an old Challenger can't be modified to do the same things. There are a handful out there that have been made to do just that. The only problem is that they are mostly a new sports car chassis and suspension with old school sheetmetal. I would love to have a car like that, but I don't have that kind of time and money.
Aiming for the overall performance levels of a new Challenger, Camaro SS or Mustang GT is reasonable if you have the cash to put alot of "XV, or Hotchkis type" parts on the car.
Be prepared though, doing a serious build like these can take piles of cash or piles of time and effort or maybe both. I have owned new performance cars and there is almost nothing that they aren't better at than my old cars except "looking timelessly cool".
Well chosen bolt on modifications can be done on a budget and can easily equal the performance of modern sport sedans. After going down this road myself, I stopped expecting these old monsters to be what they aren't and focused on improving their capabilities while keeping their character and style.