I was going to respond similar to 1971chall, but not as much detail.

I think the amount of mods you want to due the the challenger, is entirely up to you and money of course. If I wanted a hp monster then, I would most certain adding Forced Induction to the motor. Like said earlier when done correctly, both types are safe and efficent (KR/detonation in not your friend).

I would probably due like the OP stated, mostly bolt ons, as well as a really good tune.