I have found that wireless support is more a function of the chipset used rather than the actual card. I also have had good results with the atheros chipset cars using the mad-wifi driver under CentOS. I downloaded the driver and kernel modules from one of the 3rd party repos for RHEL4 (ATRPMSI think).
I recently found the following website taht has great info on chipsets used in many wireless network cards:
http://linux-wless.passys.nl/
This site has been a great help to me when I was shopping for newer wireless cards for my laptops.
Bob