Kismac Hardware list
( Can not post more than one hyperlink) just add the h...
trac.kismac-ng.org/wiki/HardwareList
Recommended by the Kismac team:
ALFA AWUS036s
PS: Read the FAQ, the RFAQ, Repeat.
PS2: CHECK THE CHIPSET AND FCC NUMBER BEFORE YOU BUY. (repeat that sentence in your head 999 times)
Kismac 101 Video (a good one)
http://www.youtube.com/watch?v=Pyiz2Mct6dk
Edit: If you wonder why I mention to read the FAQ and check the FCC number is because the Kismac Forum is full of people that purchased a 1) non supported USB 2) purchased a knock off or a USB where the manufacturer had silently changed the chipset. the FCC number is one of the best guarantee that the chipset is correct. Do some due diligence before buying and you'll save a lot of time, money and/or trouble. I would advise you to buy from a brick and mortar shop if you can. At least you can return the USB at no fees if not working.
Kismac Airport Extreme: The more active is the network, the faster you'll collect IV's. That simple. Nota Bene: Airport Extreme in Passive mode is stealth, Dehauth, Flood, are not. It may and will reveal your attack. Console Log keep traces of that.