well, while i'm sure there's someone out there who might disagree with me, the idea of using a pcmcia wifi card when you have the option to get an integrated 802.11x chipset, is a positively silly one. not only do pcmcia wifi cards suck down the juice (not sure where you got the notion that the integrated feature uses more power... quite the other way around), but you can't use the pcmcia slot for anything else (bearing in mind that the acer has but one slot). a CF card + adapter is just as silly, given that not only would you be using almost as much power, you would be sacrificing a lot of performace in terms of range. i used my old wifi card in my acer (i have the 102ti) just for a test, and i got barely 1.5 hrs of battery life out of it, compared to nearly twice that when the integrated wifi is in use.
of course, it depends on how much you'll use the wifi feature. given that that's the only way i get on the internet, and i can find/use a connection quite literally almost everywhere i go, having the integrated wifi is indispensible. i couldn't imagine going back to the crappy battery life of my old pcmcia card, nor that annoyance of having something delicate sticking out the side of my computer all the time. believe me, get the 102ti... you won't regret it.