Do you have some evil spirits in your house or are you trying to keep the bugs off your porch ceiling? If the latter, you should note that the original Haint Blue had Lime mixed into the milk-based paint, and it was the lime which helped to keep insects from attaching themselves to the ceiling. The paint sure looks pretty, though. Reminds me of a gentle sky.
Keep in mind that from what I've read, Haint Blue varied from region to region, as the materials varied, long before there was a paint store. So, you may see different interpretations of the color, which vary quite a bit from a light, gentle blue, to a green-blue color. I bet if you go to Frank's Cash 'n Carry, just north of Grayton, in the back of the center behind Hurricane Oyster Bar, the lady in the paint center can hook you up, if you are telling her you want ceiling porch blue. Now if you are getting it for your historical home in Savannah or Charleston, I'd say to try another method.
Have you tried going to Benjamin Moore's or Sherwin William's website to see if they have "Haint Blue?" That might also work. Surely, with the historical use of the color in places like Savannah and Charleston, there is something on the www to help you out.
edit: I see that neither BM nor SW have that color. Go to
www.myperfectcolor.com and you can match colors from all major paint suppliers. As I mentioned, the color of Haint Blue varied quite a bit, but here is one of the two colors (the more green/blue) I had in mind as Haint Blue.
Benjamin Moore 2049-60 Forget Me Not