I would do the certified 11'. The new 5.0 is a good motor but I did have a leaky water pump that I hear is common and they are known to need cam chain tensioners as well; once they are replaced with the new parts you should be good for a long time. The piece of mind is nice too plus a 11' and 12' are the same.
Do they both have the HD package? That might help you decide too.
Do they both have the HD package? That might help you decide too.