Welcome to the site!
Best of luck in your search of finding a '70-'71 Challenger.
It's sad, but I know of both a '70 R/T SE as well as a '71 R/T just sitting right now about 4-5 miles from me. The '71 will be done up nicely, but the '70 R/T SE continues to rot away as the owner is just too ignorant to part with it and see someone else restore and drive it.