SOLDIERX.COM Nobody Can Stop Information Insemination

Ok my buddy gave his r50e after he unlocked the bios since he had no use for it. After wiping it cleaning and upgrading the ram and processor, I decided to get back to penetration. I had played with backtrack before but never too much in depth. So now that I've set the stage here's my only concern: what would be best for pentesting? A wifi USB or a PCMCIA card? If it's a USB I can refer to the previous forum to find a good one. But I would first prefer a reason as which is better. Thanks guys.