<< A good "PCI" Wireless card is the Orinoco USB Client. >>
ABSOLUTELY!
If your OS and machine fully support USB...Orinoco USB client is definitely the way to go.
Resembling an external antenna, you can locate it for maximum signal strength.
PCI wireless adapters are normally little more than PCMCIA adapter cards, with a regular wireless PC card stuck in the slot.
Which means the antenna on the card is BEHIND a huge block of metal (PC case), an absolute killer of wireless signal.