Have you tried looking at OWC? I got 16Gb for my MP 3,1 a few years back and the prices were pretty good. Would love another 16Gb to feed it's hungry belly.
I may have what you want, but am not sure if my memory will work for you.I am considering upgrading my Mac Pro to 64MB, in which case, I need tosell my 16 GB boards (4 x 4GB). I am not at home at the moment, butbelieve they are the 1333 MHz boards. They are from OWC.Please contact me at : rudlinfineart@gmail.com This might work outgreat for both of us!craig