Device to use for Backtrack / network security
I am just getting into network security and forensics. I am learning how to hack into networks both for education to know how to, and to be able to know how to prevent others from doing the same. What I have is a laptop with windows xp, and a desktop with windows 7. For this, I will be putting linux on one / both as either a full install, or at first probably a live CD of backtrack. What I still need though is a wifi card, and that is where I am having trouble picking one out. If anyone can help me find one that fits my needs, as I am not sure what to go with, or their differences at this point. But what I would really like to have is a USB card with B, G, and N. If anyone can offer me some ideas / solutions / help that would be great.
Thanks!