The Six Griffons Haunt is now in print at Paizo.com, so it's now in print from anyone that sells it online.  You can also get the print and .pdf as a bundle together--I recommend this, so you get the printable full-color maps for your gaming table as well as the print adventure itself.

I also have print copies for sale at Chicago-area game stores: Chicagoland Games and Games Plus, but others to come!