According to the Gateway website, it's probably a Broadcom BCM4318E...

I thought the Broadcom wireless cards were all well-supported in 10.5.1. My Compaq laptop has a Broadcom BCM94318MPG wireless mini-pci card and it worked right of the bat with Zephy...

Here's the URL for the motherboard specs:
http://support.gateway.com/s/Mobile/Q106/Bishop/4001189R/4001189Rsp4.shtml

The onboard LAN adapter is the infamous PHY8201 ( Realtek RTL8201CL ) that may be tricky - I haven't been able to get mine to work...

The audio is a SigmaTel 9200 - I've never heard of it. You'll probably have to search InsanelyMac...

Gateway.com has all sorts of interesting information...
http://support.gateway.com/s/Mobile/2007/Apache/1014552R/1014552Rnv.shtml

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Running both 10.5.8 and 10.6.4 on my stinking AMD/ATi machine...