Linux has a larger community of, sometimes company sponsored, developers than the BSD's
On most BSD's you usually have a greater chance that your hardware is recognized by the kernel, when the hardware is not that bleeding edge anymore
I hope you find a good card.
If you would have been running OpenBSD I would have advised you to try OpenBSD current, the development branch.
The last official NetBSD release, 5.1, was released in Nov 2010. That is more than a year ago.
You still could try the latest NetBSD before you spent your hard earned cash on more hardware
See
http://netbsd.org/releases/current.html for information about the NetBSD current development branch.