For what its worth, and if you are looking for a full range speakers, Altec 604 Series have 8 or 16 ohms, have that 8 pattern hole and are 15" in diameter. The 604-8G's can be mounted front or back of the baffle while the 604 B,C,E, and D have to be mounted at the back only (I think!).
For new production drivers in the Altec tradition, check out Bill's site here http://www.greatplainsaudio.com/
and pay attention to the 604-8H-II.
Disclosure: I am an Altec 604-8G /SET/Cornet2 user.