Boss 429 or Shelby GT500/500KR

[m19gale]

Hello, I am looking to purchase one of the above and need some help in locating good cars. Preference is Red, black or white. I am by no means an expert and the small details can make or break a car. I am preferring non restored first, original drivetrain, but will consider restored. But most inportantly, I want a no issues car without questionable history. Any help is appreciated. I am looking for a car to keep for a long time and keep in the family.
I appreciate the help in advance.