Hi,
I have a 320 with a TP16 mk IV. I use an Audio Technica AT440ML OCC, no longer available and replaced by the AT440MLa.
If I were to do it over, I'd ask myself this question - Do I have a bright system? If the answer is yes and you like that, I'd suggest an Audio Technica 150MLx. That's essentially a 440ML with beryllium cantilever. That should do the trick.
If the answer is yes and you don't like that, something more mellow would do.
If the answer is no and you want that, again the AT150MLx.
If the answer is no and you don't want that, something more mellow like a Grado will do you well.
Regards,
Don