The ZM-80 needed quite a bit of paste in the presence of the GPU shim in order to make good contact. The updated ZM-80A has a relief milled around the edge of the GPU contact block, thus avoiding contact with the shim; since this allows for the block to make contact with the GPU, only a thin layer of paste is required.
I use a ZM-80A on my 9700 Pro (non-AIW) and am very pleased with the result. Only recommendation I have is to replace the generic white paste which ships with the Zalman with something better; I used AS Ceramique.
I noticed on the Zalman website they do not recomend on system where the AGP slot would have the card sitting horizontal and since my box is a tower with the AGP in the same plane as the PCI slots my ATI AIW 9700 Pro would indeed be horizontal. Hows your setup?
In fairness, my case has side fans that pull in fresh outside air and blow right at the AGP slot so I would think I could use it. I need to takes some measurements to see it there will be any problems installing both the ZM-80A and the CNPS7000-Cu on the CPU.
Can you tell me if you had any difficulty mounting this HS?