Sorry I cannot help you in the wifi card thing, but i would like to say a few words about pdaXrom in general.
pdaXrom is much closer to other desktop Linux distros than Sharp/Cacko. Almost all the apps for pdaXrom are directly (and can be relatively easily) compiled from the available sources. And they run smoothly (even for big guys like Firefox, GIMP and gumeric)!
The official feeds already have lots of packages. Yet don't forget to check out the contrib feeds and quite a feed individual feeds of some members here, including the "New Packages Announcement" thread. They have kept growing with tons of nice packages ready to use!
I'd say after using pdaXrom for more than a year, I find myself having much less frustration with lack of useful packages and with platform specific issues now than when I was using Sharp rom in the old days.
P.S. It's interesting to see more and more folks (I am one of them, hehe...) are going for having 2 Zs, one for real use and the other as a laboratory. My C1000 is now running Beta3 and feels quite rock solid, whereas my C860 (Beta1 -- or see my signature) has been awaiting quite a while for a more stable beta to test and to crash.