Wow, I'm dumb. Nevermind, you have the card already.
Answer: No. Your chipset is nVidia SLi not CrossFire so you can only go single GPU or SLi. Sorry.
But, for $200 I'd get:
Sapphire X1300XTx2
Answer: No. Your chipset is nVidia SLi not CrossFire so you can only go single GPU or SLi. Sorry.
But, for $200 I'd get:
Sapphire X1300XTx2