Where did you get that particular info? Doesn't seem to be a valid Mac model. Can you check again? The processor speed on an iMac G5 will tell most everything, with the display size (17 or 20-inch)
Any iMac G5 prior to the iSight models take PC3200 SDRAM - each slot up to 1 GB.
The hard drive is SATA 3.5-inch, so you can upgrade to 2 TB if you want.
The Airport card, again, will depend on which model you have.
The first G5 iMac was an optional airport or bluetooth
The next model (known as ALS) has a combined Airport/Bluetooth card, which was not optional. Another way to tell is the combined card will have two antennas connected, and is mounted directly on the logic board. The older, Airport extreme is a standard Airport extreme card mounted in a grey plastic bracket, with only one antenna.