I used to use the Orinoco Proxim Gold 802.11 b/g atheros based wireless card for wireless scanning. It was great for its time, then we were introduced to the Ubiquiti DMARC 300mw 802.11 a/b/g wireless cards. Yes, they are expensive but they work awesome. For example I was conducting an "Authorized" wireless pentest from the parking lot of a customer. It was approximately 500-750 ft away from the bldg, not the AP, so can probably add other variables like structure, location of AP in the bldg etc etc. Well, I was able to sniff packets without having an antenna attached to my card. Yes, I was dropping a few packets here and there, but for the most part, I was actually capturing packets on this device. Oh and I guess it also helps that I was using on of the greatest wireless analyzers around "Kismet". (Last line added for effect!!) I then proceeded to put the little antenna that came with the card that fits in the pigtail port and "shazam"... I had full packet capture with awesome signal strength. Not only is this card great for range and packet capture, but it works great for packet injection as well. So, to make a long story short, these Ubiquiti cards are awesome. Yes, they're expensive, but well worth the money for those that conduct wireless assessment regularly. Oh and on another note, this is somewhat related, another good card to look at is the USB Airpcap wireless 802.11 a/b/g , I like this card because it does everything the Ubiquiti card does but works in a VMare machine as well....and I think that is awesome for more strealth Red Team type of assessments.
Thanks for listening...
have a great holiday everyone