Yeah, the ZM80A-HP and ZM80-HP both fit the 9700/9700 Pro. (The only difference between the A and the standard is a slight recess at one edge of one of the heatsinks to compensate for possible install problems.) You do have to put a little more goop on it to to make up for the gap between the shim and the processor, but it's easy enough, even for me.
However, the heatpipe gets very hot to the touch on the 9700 (on my Pro anyway), and I think to be on the safe side it's good to have sufficient cooling in the case. That said, I haven't had a single issue with the video card at all. When I first installed the heatpipe, I ran 3Dmark2001 on infinite loop while I ran errands for the better half of the day. When I came back, it was still going strong.