5900 Ultra / Zalman ZM80C-HP

Does anyone know whether the Zalman ZM80C-HP with ZM-OP1 fan is up to
cooling a GeForce 5900 Ultra?

If it is, does anyone have any experience of fitting it? I have the PNY
version of the card. It looks like it has HSF mounting holes in the
standard locations. The connector on the card for the stock HSF looks like
a generic system fan connector - is this the case, & so could it be used to
power the ZM-OP1? I am concerned that the switching between high & low fan
speed controlled by the GPU not be compromised.

What about the RAM chips? On the PNY part of the stock heatsink covers
these. Does the ZM80C-HP contact these (looks like not from the pics on
their site), & if not is it possible / necessary to use a passive heatsink?

Thanks in advance for any advice & info.