I'm not sure what power connection the 9700 will need exactly, but you should easily be able to buy an extension or splitter cable for your power supply to hook up to the card. There's no need to sacrifice an existing connection because of a new peripheral.
My only real concern based on what you've asked is the size and quality of your power supply. If you're at your limit of connectors then you might want to look critically at whether you'll have enough juice to run a stable upgraded system.
I fart in the face of normality