Hanging after-market fan off of a 4870

Hi, all.

I have an ASUS EAH4870 Deluxe.

The fan on this card is louder than I'd like when the card starts to
work.

So I've decided to replace the cooler with a Thermalright T-RAD2
cooler, and 2 Zalman ZM-F2 92mm fans. The box of bits just showed up.

What I would like to understand is whether there is any *safe* way to
plug two aftermarket fans onto the power plug on the card, to put the
fans under speed control by the card. Is that just a bad idea? If it's
reasonable, how would the fans be plugged in? Series? Parallel? I have
a variety of connectors which would make either orientation possible.

One alternative would be to simply hang the fans off the computer's
PSU and (optionally) use a manual speed control on the front of the
case.

Maybe the *best* idea would be to plug the fan which would actually
sit overtop of the GPU into the card, so it is speed-controlled by the
card, and hang the other fan off the PSU of the computer and just
leave it running at a static speed.

Feedback appreciated.

Thanks!

BD