Very nice job and thorough write up on what your process was and everything. I won't be painting my car but I'm getting someone else to do it and I would like him to do as good of a job as you're doing. Anything I should tell him how I want my paint? Because I really don't want a mediocre paint job and want to be satisfied with it.
Thanks for the kind words.
I would study up on the process that was needed for your car. Find out which of PPG's systems are used for your color of paint.
Study every product associated with the complete paint job as though you were going to do the work yourself.
Seek out someone that swears by PPG paint. If the guy you talk to says he uses DuPont paint...well...I'm sure I'll get flamed but tell him "thanks, but no thanks". Once I started to used the products I was able to detect the fact that everything DID work together as a system. Each and every coat I applied -12 total- did exactly what it was supposed to do (one epoxy, 3 surfacer, body work, one more epoxy and 2 more surfacer, 3 basecoats and 2 clearcoats - separated by a 400 grit wetsand). And this was only my second complete paint job. I know someone right now is saying "If it did what it was supposed to do you wouldn't have needed 12 coats"...and to this I say...

It wasn't the paint's fault...It was because I didn't know what I was doing.
I used a $30 gun but I made damn sure I had plenty of air. If the guy is experienced and suggests using Shopline paints, he's probably more capable than me.
Don't let him use a single stage paint when the original paint was a base-clear. PPG has a line called "direct gloss". It's fantastic for jambs and engine compartments, and in the right hands, it's great for spot repairs, but it's not the right product for an all over job.
From my research, I found there are two methods that are most common for preparing the surface for the color coat. Wetsanding the final primer coat to a baby-ass smooth 600 and then shooting the base/clear (you can take all month to nitpic the surface this way) or just scuffing the final primer coat and then shooting a sealer immediately before the first base coat.
The latter is what you will see in most production environments. They have the facility, the equipment and the skilled painters to pull that off. Being a noob, I chose the former so that I could wetsand the primer to a more consistent finish and so that I could cut down on the total number of coats of paint I was going to use on that final session by eliminating the final sealer (I got away with that because there's epoxy under there, sealing in the body work).
Also, did you replace the molding around the windshield and rear glass? If you did, where did you get it?
I had the windshield replaced, you can see that in one of my posts in this thread or maybe my other paint related thread. The rear glass was tough but I was able to mask it well enough and I spent several hours on that area alone, fixing where the surfacer puddled against the lip of the seal. It's still not perfect, and it's an area you'll want to pay attention to. It looks like an OEM windshield seal would work ... if you could find one of those... I was able to remove mine in one piece but I didn't try very hard to remove the rearglass seal since I was afraid it was too brittle.