How important is it to change the cam and crank bolt when changing a cam. And if I do where else could I get them other than ZZP or intense

Those are torque to yeld, so they are stretched. I say change them. I got mine from ZZP

Technically they are TTY and GM will tell you to replace them. Because of the way they hold things etc, it doesn't seem to be an issue. I've never replaced mine and always reused them. I don't recommend replacing them.

Rocker bolts and rotating assembly bolts are the only ones I always recommend.