G4 Ti DVI 1GHz && Airport Extreme

This machine comes with a Airport card, but I want/need the Extreme...

Is it possible to upgrade the machine? I can't find a PCMCIA Extreme card (?!) on eBay. All of them have some other card slot (which doesn't exist in my machine).

I talked to a Mac specialist company and they said that I could put a card named 'Sonnet Area Extreme' in the "externaly accessible slot". I'd still have to remove the AirPort...

"Long time ago" I worked for an ISP which sold radio links (I only worked in the office with servers etc) and there i 'accidently' (ehm... took apart a PCMCIA WiFi card.... I.e. I removed the antenna...

Shouldn't this be possible? Remove the antenna on the Sonnet card and put it in the AirPort slot (the non-externaly accessible slot)?

The company I talked to said no (but gave no reason even though I asked for one - experts or wannabees?)...