If the card has active cooling you should be AOK. But if you buy that TYAN card I pointed out to you youll be even better. Massive heatsink and active cooling on that puppy.
But if it ever becomes an issue theres solutions. You can make a vid card intake fan on the side of your case, you can buy a cooling fan that fits in a PCI slot (tho they tend to be cheaply made) or you could TRY one of those massive aftermarket card cooling heatsinks.
But Ive really never heard of a 9800Pro overheating.... so long as your case has some airflow you should be golden.