Reason you have issues is you copied 2 kexts from a MBA thinking that would magically make it work, don't do that. Have patience and wait for the proper support in 10.8.5 and 10.9. I can verify it works as advertised in both those versions.
I would like help. I have the PCE-AC66 and I only have channels 1-11 as supported channels in 10.8.5 with the supplemental update. This means I cannot see any 5ghz channels. The card works perfectly in Windows 8 x64 as I can see the two 5ghz ssids that I set up (main router is rt-n66u in the main house running merlin and I have an rt-ac66r running dd-wrt in repeater bridge mode in the cottage where I am). Who knows what is happening?