I stopped by the paint store again.  I got them to price match Amazon on a DeVilbiss GTI.  It has 1.3mm, 1.4mm, and 1.5mm tips.  I plan to use this for single stage and base coats, it's a step up from the DeVilbiss Finishline I have now.  I also bought an Anest Iwata LPH-400LV clearcoat gun, it will be in next week.

The paint booth was plumbed with PVC pipe, which is generally considered extremely dangerous.  It's known to explode spontaneously, especially after some UV exposure - this is right next to the garage door. 

I used 1/2" black iron pipe.

I replaced the coarse filter too, there were two smaller ones that were restrictive.

This is the desiccant dryer setup in the booth, it works pretty well.