Will I be sorry?

Jumping in a bit late, but... If you can do the prep yourself, that's usually the weak link in the paint jobs from franchise shops, whether it be Macco or the Earl. Have everything sanded, trim removed, dents filled, etc., when you bring it in. Bring your own paint if you have special desires that they might not be able to match. But when it comes to the actual painting, those guys shoot more cars in a day than you'll do in a lifetime, so they've got the skill and the tools. And they need to get it right the first time because if they have to reshoot it, they lose money, so there's plenty of incentive to get it right, especially if they can see that it's a project car and not just someone's daily driver in need of a new look.