Thanks Mark. I'm thinking if nothing else turns up I'll probably use just the DIP16 version of the 74HC279 which I was able to locate and SMD versions for the rest. I figured I could save a little bit of space if I soldered the DIP packages just like the SMD chips (i.e. not drilling holes but bending the legs to the side and soldering on the component side)...
Edit: Yes, the latches are not identical but you can treat them as identical if you just connect both of the /S pins together on the double input ones...